One shot

Out of all the vaccines created to protect us, there’s only one we need to get every year: the flu shot. A team of engineers and scientists are working to change that. They envision a day where one shot will protect you for life and recently had a breakthrough which could help improve current vaccines[1].


“Worldwide, half a million people every year die from flu globally,” said Jiwon Lee, a doctoral student who was part of the team. “So it is a big problem that still affects our daily lives and also there’s a huge economic burden from getting sick with flu.” However the number of deaths vary widely each season as different strains of Influenza Virus circle within the population. Even the American Centers for Disease Control and Prevention (CDC) does not know exactly how many people die from seasonal flu each year[2].
Lee says the team was able to uncover a new class of antibodies to protect the body from several flu strains, successfully working on mice. They were able to make the discovery with the help of new technology, which they say could be the key to better understanding the virus and how to beat it.

“This information can be used to redesign the vaccine and we can test it using our technology to understand if it’s working or not,” said Lee.

The team also studied current vaccines, quadrivalent and trivalent influenza vaccines. Quadrivalent is currently recommended by the CDC to protect against four virus strains and trivalent protects against just three. Researchers say while both are effective, trivalent still produces antibodies to protect a person from the four strains, meaning this may be the most cost-effective option for the public.

According to the CDC, influenza is the eighth leading killer in the United States. Lee hopes their research could better protect millions someday. “Develop a universal vaccine where you receive it as a kid and you’re protected for life against all the known viral strains,” said Lee.

“By engineering or designing the correct or the best fragment of the virus to put in the vaccine, that’s the goal,” said Lee.

[1] Molecular-level analysis of the serum antibody repertoire in young adults before and after seasonal influenza vaccination in Nature Medicine – 2016
[2] Estimating Seasonal Influenza-Associated Deaths in the United States: CDC Study Confirms Variability of Flu. See here.

Influenza A (H5N6) Virus has reassorted (again)

Avian influenza A(H5N6) viruses have circulated among poultry in southern (Jiangxi, Guangdong) and western (Sichuan) provinces of China since 2013. In 2014, outbreaks of H5N6 virus infection occurred among poultry in China, Laos and Vietnam. In April 2014, the first case of highly pathogenic H5N6 infection among humans was detected in Sichuan Province; the second case was detected in December 2014 in Guangdong Province. In December 2015, four humans in Guangdong Province were infected with Influenza A (H5N6) Virus.

Since emerging in 2013, Influenza A (H5N6) Virus has managed to reassort with both Influenza A (H9N2) Virus and Influenza A (H6N6) Virus in Guangdong (China). Two of the three isolates examined also appear to have picked up genes for amantadine (an older antiviral) resistance, that was not present in 2014[1].
The authors suggested there may be other - as yet undetected - H5N6 reassortants in the wild and others may yet emerge.

Then, during the last week of November 2016, Korea's Ministry of Agriculture released a preliminary genetic analysis of four recently obtained Influenza A (H5N6) Virus samples from South Korean wild duck's feces and compared them to the same virus subtypes collected previously from Mainland China and Hong Kong[2].
The analysis showed the Korean Influenza A (H5N6) Virus has changed internally from its predecessors, and that its genetic evolution continues unabated. While Korea's Influenza A (H5N6) Virus' HA and NA genes are roughly a 99% match to earlier samples, some if its internal genes have changed - likely through reassortment - and at least one (PA gene) is only about a 92% match to previous samples. It seems very likely that the virus picked up these changes as it circulated among birds in their summer breeding areas of Siberia and Northern China.

Exactly how these genetic changes might affect the behavior of the virus – if at all – isn't yet known, although Korea's CDC is conducting tests to determine its potential pathogenicity in humans.


[1] Novel Reassortant Avian Influenza A(H5N6) Viruses in Humans, Guangdong, China, 2015 in Emerging Infectious Diseases – 2016
[2] MARFA: H5N6 type AI virus gene analysis Intermediate results (November 28th, 2016)

Influenza A Virus in Bats [2]

Here I wrote about the discovery of two novel Influenza viruses in Central and South-American bats. Previously and provisionally designated Influenza A(H17N10) and Influenza A(H18N11), further research has revealed some worrying facts[1].

As is usual, Influenza subtypes are named by their (simply increasing in number of discovery) hemagglutinin (HA or H) and neuraminidase (NA or N) proteins.
Studies indicate that H17 and H18 HAs are unable to bind and hemagglutinate red blood cells and therefore are not “true” HAs. Thus, the scientists suggest that HAs from both H17 and H18 influenza A-like viruses should be named as “HA-like” (HL) proteins (HL17 and HL18). The N10 protein exhibits no or extremely low NA activity suggests that it may have a different function than the NA proteins of other influenza viruses. The scientists therefore suggest that N10 and N11 from bat influenza A-like viruses should be designated as “NA-like” (NL) proteins (NL10 and NL11)[2].

The new provisional naming of these two viruses is therefore: HL17NL10 and HL18NL11.

Several lines of evidence indicate that bat Influenza A-like viruses are of low risk for the human population. Yet, the evidence also suggests that the ability of HL18NL11 or HL17NL10 viruses to infect canine and human cells might reflects a zoönotic potential of these recently identified bat viruses.

[1] Moreira et al: Synthetically derived bat influenza A-like viruses reveal a cell type- but not species-specific tropism in Proceedings of the National Academy of Sciences of the United States of America – 2016
[2] Wenjun et al: Expected and Unexpected Features of the Newly Discovered Bat Influenza A-like Viruses in PloS Pathogens - 2015

It's official: Influenza D Virus

Late in 2013, I wrote here about the discovery of a novel Influenza Virus that was then tentatively called Influenza D Virus to reflect its similarities and differences with the other Influenza viruses.

Now, late 2016, the executive committee of the International Committee of Taxonomy of Viruses officially approved naming the new virus, influenza D. The committee officially announced a new genus with a single species, Influenza D virus, because of its distinctness from the other Influenza types — Influenza A, B and C.
Though Ben Hause isolated the virus from a diseased pig in 2011, he later found that cattle were the primary reservoir for influenza D. This was the very first Influenza Virus identified in cattle.

Ultimately, the goal is to determine whether influenza D, which has 50 percent similarity to human influenza C, can cause problems in humans. However, the scientists involved, Feng Li and Radhey Kaushik, claim that “the virus has not been shown to be pathogenic in humans. No one should be afraid of this.”

Somehow they seem to forget the lessons from other Influenza viruses: they reassort frequently, mutate readily and have pervasive antigenic shifts and antigenic drifts. Why should Influenza D be different? “We have much to learn about this new virus,” said Li. That much, at least, is true, because a study indicates that the virus may be an emerging pathogen among cattle-workers.

Tick bite may trigger severe meat allergy

People living in tick-endemic areas around the world are being warned of an increasingly prevalent, potentially life-threatening side effect to being bitten: developing a severe allergy to meat[1]. Sudden onset meat allergies (officially called Alpha-gal allergy) are exceedingly rare in adults who have never been bitten by ticks. Alpha gal is a sugar, present in beef and pork (as well as the meat of all other mammals that are not primates).
Sufferers of 'tick-induced mammalian meat allergy' will experience a delayed reaction of between two and eight hours after eating red meat. Some immune systems are sensitive to proteins in the parasite’s saliva and become intolerant of red meat and, in some cases, derivatives such as dairy and gelatine. Poultry and seafood can still be tolerated. Symptoms include severe whole-body itching, hives, angioedema, gastrointestinal upset and possible fatal anaphylaxis.

Cases of the allergy have been increasingly reported in Europe, Asia, Central America and Africa, but it is most prevalent – and on the rise – in parts of Australia and the United States. Some Australian doctors now diagnose one to two patients every week.

Due to the role of cofactors like exercise, alcohol consumption and other medication in allergic reactions, and the risk of death that comes with anaphylaxis, many often follow vegetarian or vegan diets. Sufferers are also advised to prepare their food at home, as fish and poultry are often combined with mammalian meat products such as stock, and to avoid cross-contamination between utensils and cooking surfaces.

[1] Van Nunen et al: An association between tick bite reactions and red meat allergy in humans in Medical Journal of Australia – 2009

Original Antigenic Sin

The concept of 'Original Antigenic Sin' for influenza--which proposes that immune memory of previously encountered older flu strains weakens the response against threats from current strains--has been around since the 1960s. The idea is that, because some parts of a current flu virus are familiar to the immune system, antibodies specific to older flu strains are 'recalled' and produced at the expense of the creation of new antibodies specific to the current strain, and that these 'original antigenic sin' antibodies are detrimental to the host since they react poorly with the current strain against which defense is needed.
To study 'original antigenic sin' antibodies, researchers studied antibody responses in mice that were sequentially exposed to different influenza strains[1]. Most antibodies against influenza viruses recognize one of two highly variable proteins on the virus surface. The researchers focused their analysis on the antibody repertoire against one of them, hemagglutinin, or HA.

Human antibodies elicited by influenza viruses often bind with a high affinity to past influenza virus strains, but paradoxically, do not bind to the viral strain actually eliciting the response. This phenomena is called 'original antigenic sin' (OAS) since this can occur at the expense of generating new de novo antibodies. The researchers characterized the specificity and functionality of antibodies elicited in mice that were sequentially exposed to two antigenically distinct H1N1 influenza virus strains. Many antibodies elicited under these conditions had an OAS phenotype, in that they bound strongly to the viral strain used for the first exposure and very weakly to the viral strain used for the second exposure. It appeared that OAS and non-OAS antibodies target the same general region of the influenza hemagglutinin protein and that B cells expressing these two types of antibodies can be clonally-related. Surprisingly, although OAS antibodies bound with very low affinities, some were able to effectively protect against an antigenically drifted viral strain following passive transfer in vivo. Taken together, the data indicates that OAS antibodies share some level of cross-reactivity between priming and recall viral strains and that B cells producing these antibodies can be protective when recalled into secondary immune responses.

[1] Linderman et al: Antibodies with 'Original Antigenic Sin' Properties Are Valuable Components of Secondary Immune Responses to Influenza Viruses in PLoS Pathogens – 2016

Influenza Vaccine and Tobacco

At the moment, the Influenza vaccines are produced in chicken eggs. This can cause problems In rare cases in people that are allergic to chicken protein. The biggest problem, however, lies in the time it takes to produce: it takes six months before sufficient vaccine is available, which is far too long if a novel Influenza variant suddenly emerges.
Medicago, a Canadian company, has developed a technology wherein genetic Influenza-material (virus-like particles or VLP) is implanted into tobacco leaves[1]. Because tobacco leaves grow quickly, more virus-like particles are produced. The production process is six times faster than the older process in chicken eggs. Plus it's a lot cheaper.

At this moment in time you are probably wondering why this vaccine isn't available yet. The hurdle is that every medicine needs to undergo various test phases to study if it doesn't pose any danger to humans and if it does what it is proposed to do. It has now been entered into the so-called Phase III and thus the end is in sight, because there is only Phase IV to sustain before the vaccine is ready to go to the market.

[1] D'Aoust et al: The production of hemagglutinin-based virus-like particles in plants: a rapid, efficient and safe response to pandemic influenza in Plant Biotechnology Journal – 2010

Influenza and Air Pollution

In recent years China's deteriorating air quality has increasingly been suggested as a potential co-factor driving the severity of their yearly flu seasons. Particularly, but not exclusively, the effects of fine particles less than 2.5 micrometers in diameter[1].

There have already been number of studies that have found an apparent correlation between the level of air pollution and respiratory outbreaks in China[2][3].
The age groups most affected by increased dust and pollution vary by study. There is a lot we still don't know about the environmental effects on influenza.

These days, each winter - between November and December - much of the Eastern seaboard of China is plagued by heavy and persistent haze and smog. At the same time, reports of extremely heavy pediatric respiratory outbreaks appear[4]. Dozens of similar reports came in from Anhui province, Jiangsu Province and Liaoning Province.

A letter to the Editor of the American Journal of Infection Control that not only describes the extent of the outbreak in Shanghai in December, 2015, it also discusses its potential link to the Shanghai's poor air quality last winter[5]. “The epidemiologic association between the occurrence of haze and the incidence of influenza A virus infection remains largely unknown. However, during the widespread and dense haze events that occurred during the winters of both 2013 and 2015, we observed a sharp increase in the number of patients with respiratory tract infection, especially influenza A virus infections”.

The researchers pose themselves a series of questions. Is the particulate dense air inhaled into the respiratory tract during a haze event a vector for pathogens, including influenza A virus? Does heavy haze decrease the resistance of lung tissue to pathogenic microorganisms, thereby increasing the risk of respiratory disease? Does influenza A Virus merely happen to coincide with the seasonal haze?

[1] Feng et al: Impact of ambient fine particulate matter (PM2.5) exposure on the risk of influenza-like-illness: a time-series analysis in Beijing, China in Environmental Health – 2016
[2] Liang et al: PM2.5 in Beijing - temporal pattern and its association with influenza in Environmental Health – 2014
[3] Huang et al: Acute effects of air pollution on influenza-like illness in Nanjing, China: A population-based study in Chemosphere – 2016
[4] Ouyang: China wakes up to the crisis of air pollution in The Lancet – 2013
[5] Qingchun et al: Haze and influenza A virus: Coincidence or causation? in American Journal of Infection Control - 2016

Influenza D Virus – Part 2

Here, I had already predicted that the newly discovered Influenza D Virus might be a harbinger for trouble. First discovered in pigs in the US in 2013, it was strangely also present in cows in France and China. Sheep and goats were also shown to be susceptible to this Influenza D Virus. One could speculate that the virus might have gone undetected for quite some time before it was discovered.

That, however, was the good news.
Scientists from Florida (USA) wanted to know if individuals working with cattle could become infected with Influenza D Virus. They investigated serum samples from 35 cattle-exposed and 11 non-cattle-exposed adults. A seroprevalence of 91% was detected via HI assay and 97% by MN assay. Among non-cattle-exposed individuals, seropositivity determined via MN assay (only) was lower (18%)[1].

Whereas it is still unknown whether Influenza D Virus causes disease in humans, the study indicates that the virus may be an emerging pathogen among cattle-workers.

[1] White et al: Serologic evidence of exposure to influenza D virus among persons with occupational contact with cattle in Journal of Clinical Virology - 2016

MERS-CoV mutations in South Korea

Middle East respiratory syndrome coronavirus or MERS-CoV was first reported in September 2012 in Saudi Arabia. Investigations later identified that the first known cases of MERS occurred in Jordan in April 2012. MERS causes a severe respiratory infection with a high case mortality rate (~35%). To clarify: MERS-CoV causes MERS.

So far, all cases of MERS have been linked through travel to or residence in countries in and near the Arabian Peninsula. From May to July 2015, a large outbreak initiated by an infected traveler from the Arabian peninsula swept South Korea and resulted in 186 confirmed cases with 38 deaths (case mortality rate: 20.4%).
Korean Researchers detected a mutant MERS-CoV during that outbreak[1]. They isolated 13 new viral genomes from infected patients and found that 12 of these genomes possessed a mutation in the receptor-binding domain (RBD) of viral spike (S) protein.

Strikingly, these mutations result in reduced affinity. This unexpected finding suggest that the virus adaptation during human-to-human spread may be driven by host immunological pressure such as neutralizing antibodies, resulting in reduced affinity to host receptor, and thereby impairs viral fitness and virulence, rather than positive selection for a better affinity to CD26.

In short, the human immune system may work so effectively that the Middle East respiratory syndrome coronavirus has been forced to adapt itself to survive. In doing so, it made itself less fit to infect humans. It's a strategy that was very effective in the past for the Influenza virus, because it was a sort of 'stepping stone' to become more virulent in the next phase of the process of mutation.

[1] Kim et al: Spread of Mutant Middle East Respiratory Syndrome Coronavirus with Reduced Affinity to Human CD26 during the South Korean Outbreak in mBio – 2016

Influenza A(H1N1)pdm09 Virus continually mutates

Influenza A(H1N1) Virus was first observed in Mexico in 2009 and managed to become pandemic in a matter of months. A vaccine was quickly developed and now you simply have to get your yearly jab to be safe from a potentially life-threatening infection.

But, like I said so many times before, the virus manages to evade a vaccine time and time again. So, what if you end up in hospital as a result of a somewhat mutated virus? Doctors starts treating you with Neuraminidase Inhibiting (NAI) antiviral drugs like oseltamivir (Tamiflu) and zanamivir (Relenza), because the Influenza A(H1N1)pdm09 Virus has remained conveniently susceptible to these NAIs.
The circulating Influenza A(H1N1)pdm09 Virus seems to mutate like all other strains before it. Scientist hoped that rates of resistant H1N1 viruses would remain low

We have seen a few worrisome clusters of NAI resistant flu, which have raised concerns that we could one day see a an antiviral resistance in our current H1N1 strain. That day seems to have arrived, because scientists founds an elevated number of NAI resistant viruses with 'permissive mutations' circulating in Japan and describes the discovery of resistant pH1N1 carrying a G147R substitution that conferred resistance to both oseltamivir and peramivir[1].

The first widespread community cluster of the H275Y mutant A(H1N1)pdm09 virus was detected in Newcastle (Australia) in 2011[2]. The H275Y substitution in the NA protein would destabilize the mutant virus. However, two additional V241I and N369K substitutions in the NA of H275Y mutant viruses were reported to increase their replication and transmission fitness, contributing to efficient transmission.

Almost all recently circulating A(H1N1)pdm09 viruses possess these permissive substitutions, suggesting an increased risk for H275Y mutant viruses to emerge and spread globally.

[1] E Takashita et al: Influenza A(H1N1)pdm09 virus exhibiting enhanced cross-resistance to oseltamivir and peramivir due to a dual H275Y/G147R substitution in Eurosurveillance - 2016
[2] Hurt et al: Characteristics of a widespread community cluster of H275Y oseltamivir-resistant A(H1N1)pdm09 influenza in Australia in Journal of Infectious Diseases – 2012

Influenza and arthropods

The huge diversity of negative-sense RNA viruses in insects, spiders, ticks and other arthropods suggests that these animals could be central to virus origin and evolution.
Researchers sequenced all of the RNA extracted from 70 arthropod species collected across China. Within this RNA they uncovered the genomes of 112 new negative-sense RNA viruses, and they inferred the evolutionary relationships between the viruses using phylogenetic trees based on the RNA polymerase gene[1]. They found that the 112 new viruses were spread across the major lineages of the negative-sense RNA viruses. These discoveries fill some major gaps in our knowledge, and allow the tree of viral relationships to be updated. For example, this latest work confirms that the viruses of the Arenaviridae genus—which generally infect rodents—belong to the Bunyaviridae family along with two previously unclassified genera of viruses that infect plants[2][3].

This study also raises some exciting new questions. For example, while many of the negative-sense RNA virus lineages were found in the arthropods, some were striking in their absence. Amongst the virus family Orthomyxoviridae, for example, they identified many relatives of the Quaranja viruses, which infect ticks, but none that are closely related to the Influenza viruses that infect vertebrates.

[1] Li et al: Unprecedented genomic diversity of RNA viruses in arthropods reveals the ancestry of negative-sense RNA viruses in eLife – 2015
[2] Ecker et al: The Microbial Rosetta Stone Database: a compilation of global and emerging infectious microorganisms and bioterrorist threat agents in BMC Microbiology – 2005
[3] Kormelink et al: Negative-strand RNA viruses: the plant-infecting counterparts in Virus Research – 2011

First cell-based four-strain flu vaccine gets FDA approval

Seqirus has announced that the US Food and Drug Administration (FDA) has approved their Flucelvax Quadrivalent™ (Influenza Vaccine), the first four-strain, cell culture-derived, inactivated seasonal influenza vaccine for people aged four years and older. Flucelvax Quadrivalent helps protect against the two influenza A viruses and two B viruses recommended by the World Health Organization (WHO) and the FDA for the current influenza season.
The traditional seasonal influenza vaccine is a trivalent formula consisting of two strains of influenza A viruses and a single strain of influenza B virus. However, since 1985, two distinct lineages of influenza B virus have co-circulated with varying dominance. The use of a four-strain influenza vaccine like Flucelvax Quadrivalent may now provide protection against both B lineages, which may lead to a decrease in the influenza burden.

Each year in the US alone, an average of 200,000 people are hospitalized due to flu complications. To reduce morbidity and mortality resulting from influenza, the Centers for Disease Control and Prevention (CDC) encourages annual vaccination for all individuals aged six months and older.

“Despite strong recommendations for everyone in the US six months of age and older to be vaccinated against the flu every year, fewer than half of eligible people did so in the 2014-2015 season. This includes children, the group with the highest incidence during community outbreaks,” said Dr. Gary S. Marshall, Chief of Pediatric Infectious Diseases at the University of Louisville. “Even healthy people are at risk—they should be vaccinated to protect themselves and to prevent transmission to others.”

Flucelvax Quadrivalent is produced using the same full-scale cell culture manufacturing technology as its predecessor Flucelvax™ (Influenza Vaccine), which allows the potential for rapidly increased production of flu shots in response to outbreaks or pandemic. Cell culture technology does not depend on eggs for manufacturing, and the vaccine is produced in sterile bioreactors. The change to using cells rather than eggs represented the first major development in influenza vaccine manufacturing technology since vaccine production began in the 1930s.

Tilapia Lake Virus

Tilapia are species of fish that has become an important global food source due to their omnivorous diet, tolerance for high-density aquaculture, and relative disease resistance. Naturally, the ever present danger is that 'farming' of a single species of fish can lead to increased susceptibility of viruses.

Since 2009, tilapia aquaculture has been threatened by mysterious mass die-offs in farmed fish in Israel and Ecuador[1]. Scientists have now found the reason: a novel orthomyxovirus[2].
Tentatively called the Tilapia Lake Virus (TiLV), it has a 10-segment, negative-sense RNA genome. The largest segment, segment 1, contains an open reading frame with weak sequence homology to the influenza C virus PB1 subunit (Translated: with the exception of a small genetic segment, that only remotely resembled a virus associated with the reproduction of influenza C). The other nine segments showed no homology to other viruses but have conserved, complementary sequences at their 5′ and 3′ termini, consistent with the genome organization found in other orthomyxoviruses.

Tilapia with disease show swollen brains (in Israel) and liver disease (in Ecuador). In the coming weeks, the researchers will publish on the link between the Tilapia Lake Virus and an outbreak of disease among tilapia in Colombia.

[1]Aygnor et al: Identification of a novel RNA virus lethal to tilapia in Journal of Clinical Biology - 2014
[2]Bacharach et al: Characterization of a Novel Orthomyxo-like Virus Causing Mass Die-Offs of Tilapia in mBio – 2016. See here.

Influenza H5N1: What happens when a country is in turmoil

For a considerable amount of time, Egypt was a relatively tranquil and affluent country. That is, until the Muslim Brotherhood's candidate Mohammed Morsi was elected president a year after an uprising that brought an end to Hosni Mubarak's 30-year rule. During his 12 months in power, Morsi was seen by many Egyptians as preoccupied with establishing political control rather than tackling economic and social problems. Then, in July 2013, the military stepped in and Morsi was overthrown and thrown in jail.

Since then, terrorists have destabilized the country even more, and tourists, once spending millions, now have turned away from the Egyptian sun and its antiquities.
[Chart by Fred de Vries]
The effects of this turmoil is best shown in the numbers of cases of Influenza H5N1. This particularly deadly stain of the bird flu virus has been circulating in Egypt since 2006, but their health system could keep the yearly number of fatalities very low.

But for the last two years, both the number of cases and deaths have been steeply on the rise. It clearly shows the apparent break-down of the fabric of society. Chaos rules. And where chaos rules, a deadly virus takes the opportunity to infect ever more people. Check the latest numbers here.

I fear it's only the beginning.

Local ‘vaccine-free daycare’ closed for sixth straight month due to outbreak

Source: The Spudd

Local anti-vaccine couple Fran and Shiv Drasher opened a daycare center in their home for other like-minded, anti-vaccine parents. The daycare was an immediate success with families lining up to get their non-vaccinated, vulnerable children a spot at the center.

Unfortunately, the daycare was only open for a few weeks before it had to close due to a whooping cough outbreak among the children.
“Everything was going fine until one little boy got whooping cough from someone on his soccer team through vaccine shedding and it spread throughout the center,” explained owner, Fran. “At first we were all happy because it meant he could give natural immunity to all the other children. Unfortunately, the children ended up getting very ill and a few had to be hospitalized or rushed to a naturopath to get some essential oils. We were told by authorities to close our doors.”

The Drasher’s tried to fight their government oppressors and re-opened the daycare anyways, just under a different name. Again, anti-vaccine parents flocked to the center eager to have their children safe from the recently vaccinated kids infesting regular daycares.

Unfortunately, they were once again forced to close their doors as an outbreak of measles spread to all the children and several had to be hospitalized or rushed to a naturopath or homeopath.

This December will mark the sixth straight month the center, Tots With No Shots, will be closed due to an outbreak of a vaccine preventable disease.

Persistence of Antibodies Following One or Two Years of Influenza Vaccination

When you faithfully take your yearly vaccination against Influenza, you expect to be prevented from acquiring that infectious disease.

We know that antibody titers to influenza hemagglutinin (HA) and neuraminidase (NA) surface antigens increase in the weeks after infection or vaccination, and decrease over time thereafter. However, the rate of decline has been debated.
Recently, healthy adults participated in a randomized placebo-controlled trial of inactivated (IIV) and live-attenuated (LAIV) Influenza vaccines[1]. These participants provided blood specimens immediately prior to vaccination and at 1, 6, 12, and 18 months postvaccination. Approximately half had also been vaccinated in the prior year. Rates of hemagglutination inhibition (HAI) and neuraminidase inhibition (NAI) titer decline in the absence of infection were estimated.

As expected, HAI and NAI titers decreased slowly over 18 months. Overall, a 2-fold decrease in antibody titer was estimated to take >600 days for all HA and NA targets. Rates of decline were fastest among IIV recipients, explained in part by faster declines with higher peak postvaccination titer. IIV and LAIV recipients vaccinated two consecutive years exhibited significantly lower HAI titers following vaccination in the second year, but rates of persistence were similar.

Antibody titers to influenza HA and NA antigens may persist over multiple seasons. However, antigenic drift of circulating viruses may still necessitate annual vaccination. Vaccine seroresponse may be impaired with repeated vaccination. Which all means that you should be taking your yearly vaccination. Each year.

[1] Petrie et all: Persistence of Antibodies to Influenza Hemagglutinin and Neuraminidase Following One or Two Years of Influenza Vaccination in Journal of Infectious Diseases - 2015

Noroviruses and Oysters

The Norovirus species causes approximately 90% of epidemic nonbacterial outbreaks of stomach flu (or gastroenteritis) around the world. It's a pretty potent virus that was observed for the first time 1968 in children in a school in Norwalk (Ohio, USA).

Currently, the Norwalk virus is the only species within the genus Noroviruses, though some think that a further breakdown will be inevitable in the future. The virus prone to mutating. More and more serotypes are known to exist and are grouped into five genogroups. GI, GII and GIV are the only genogroups known to infect humans. GIII infects cattle and GV infects mice[1]. Porcine noroviruses belong to GII, although porcine and human noroviruses belong to different genotypes within GII.
Norovirus has received the most attention in the media because of frequent outbreaks on cruise ships. Most patients will recover from the infection after a few days of misery and a spoiled vacation, but the virus can be deadly to infants, the elderly and people with weakened immune systems.

A virus like this doesn't exist in some sort of vacuum and researchers have been looking long and hard for a host species in the animal world. Recently research was published of 1,077 samples of Noroviruses in oysters[2]. Scientists found that 80 percent of the known human noroviruses matched those found in oysters. The majority of the matches were in oysters from coastal waters and thus more likely to be contaminated with human sewage.

That means that a new and potential circular opportunity to mutate has arisen, because each virus must adapt to a new species in order to survive. People who are sick because of an infection with Norovirus have diarrhea. That is disposed of via sewers and that is often discharged into the sea in areas without proper sewage treatment plants. Oysters filter the seawater and then in turn become infected with the Norovirus. A Norovirus that adapts, mutates and forms a novel subspecies. In the end oysters are consumed raw and the cycle begins anew.

[1] White: Evolution of noroviru in Clinical Microbiology and Infection - 2014
[2] Yongxin Yu et al: Molecular epidemiology of oyster-related human noroviruses: Global genetic diversity and temporal-geographical distribution from 1983 to 2014 in Applied and Environmental Microbiology - 2015

Influenza infection might protect against unknown variants

In 1968, the then circulating Influenza A(H2N2) virus suddenly disappeared and was supplanted by Influenza A(H3N2) virus otherwise known as the Hong Kong flu. Suppose that you were born in the 50s and were at one time infected by the then circulating Influenza A(H2N2) virus, might your immune system still be able recognize that specific variant of the virus if it were ever to return?

Novel research indicated just that: years of influenza exposures plus the yearly injection of the Influenza vaccin, might even protect you from other potential pandemic Influenza subtypes. Subtypes – unlike H2N2 – you’ve never actually been exposed to.

While certainly favorable news, you're not likely to have full immunity, which means you can get seriously ill, but are not likely to die. It might just provide an 'edge' against novel Influenza infection that someone with a more immunologically naive system might not have.
Yes, I know, the study was relatively small, but the results were impressive to say the least[1]. The study used pseudoviruses bearing various hemagglutinins (the H in Influenza virusses) and they found serum neutralization titers (≥160) in 100% against Influenza A(H2N2), 53% against Influenza A(H9N2), 56% against Influenza A(H3N2v), 11% against Influenza A(H9N2) and 36% against Influenza A(H6N1). None had titers >160 to Influenza A(H7N9) or Influenza A(H7N7). Thirty-six percent to 0% had neutralization titers to various H5N1 strains. Titers to H9, H6, and H5 HA-pseudoviruses correlated with each other, but not with H3N2v, suggesting group-specific cross-neutralization.

Nature is notoriously unpredictable and we never know which Influenza virus will create havoc in the human population next year. It is therefore a sort of comforting thought to know that your yearly vaccination might help you survive that pandemic.

[1] Wang et al: Serum Samples From Middle-aged Adults Vaccinated Annually with Seasonal Influenza Vaccines Cross-neutralize Some Potential Pandemic Influenza Viruses in Journal of Infectious Diseases - 2015

Influenza A(H3N8) Virus in Pigs

Influenza A(H3N8) is endemic in birds. About 50 years ago, the Influenza A(H3N8) virus unexpectedly jumped from birds to horses, spawning a new system of notation: Influenza A/Equine-2 (caused by H3N8). See here. The location: Florida, USA.

Then, in 2004 that equine Influenza A(H3N8) virus had mutated enough to be able to jump from horses to dogs. See here. The location: Florida, USA.

The next target of the ever mutating Influenza A(H3N8) virus were harbor seals, who started dying in 2012. See here. The location: New England, USA.
We can easily follow the trail of the virus: jumping from birds to horses, jumping from race horses to race dogs, spreading through population, expanding across the USA. Another strain jumped from birds to seals.

Research indicated that the virus in seals had recently adapted to bind to alpha 2,6 receptor cells, the type found in the human upper respiratory tract.

We can ask ourselves the question which species will be next in line of the Influenza A(H3N8) virus. Novel research indicates that avian and seal viruses replicated substantially and caused detectable lesions in inoculated pigs[1]. Surprisingly, researchers could not detect specific antibodies against HA in any H3N8-infected pigs. Therefore, special attention should be focused towards viruses of the H3N8 subtype as they could behave as stealth viruses in pigs.

Now we could have stealth viruses circulation in pigs without us knowing about it. While the Influenza A(H3N8) virus doesn’t currently appear to be established in swine populations, nobody knows for sure, because pigs aren't tested.

[1] Solórzano et al: Cross-species infectivity of H3N8 influenza virus in an experimental infection in swine in Journal of Virology – 2015

Influenza A(H3N2) Virus and Parotitis

Parotitis is an inflammation of one or both parotid glands, the major salivary glands. While the inflammation may be bacterial in origin, parotitis is mostly the result of an infection with the mumps virus.

In January 2015, the Chicago Department of Public Health issued an alert to local doctors to test for both influenza and mumps, when diagnosing parotitis, as several unusual influenza-related cases had surfaced.
A month later, the CDC published an overview of the 2014-15 Influenza season and remarked that thery've seen an unusual disease activity[1].
'Since December 2014, multiple states have notified CDC of laboratory-confirmed influenza infections in persons who have swelling of their salivary glands (a condition called ‘parotitis’). Of the cases of influenza infection with parotitis that have been reported to CDC, the majority have occurred in children with influenza A (H3) infection, and have resulted in mild illness.
Parotitis is not a common symptom of influenza infection, although cases of parotitis with influenza infection have been reported in the past.'

Then, in August 2015, Eurosurveillance reported[2] that Influenza A(H3N2) virus was detected in several children with a clinical diagnosis of mumps, who were sampled between December 2014 and February 2015 in England. Sequence analysis of an A(H3N2) virus from a child with suspected mumps showed the virus was similar to other circulating A(H3N2) viruses detected in winter 2014/15, which were antigenically drifted from the A(H3N2) vaccine strain.

The question of whether this so-called 3C.2a A(H3N2) influenza virus strains have an unusual tissue distribution compared with other A(H3N2) viruses or whether a subset of children infected with any influenza strain experience parotitis remains to be determined.

[1] CDC: What You Should Know for the 2014-2015 Influenza Season. See here.
[2] Thompson et al: Detection of influenza A(H3N2) virus in children with suspected mumps during winter 2014/15 in England in Eurosurveillance – 2015

Several new Influenza-like viruses discovered

I've always maintained that the Orthomyxoviridae, the extented family that consists of several related virues, such as the Influenza viruses, might be much larger than expected. During the past year or so several new viruses have come to light. The most recent discoveries were the Bourbon Virus and the Wellfleet Bay Visrus, both in the USA.

So, what would happen if you really search for viruses in possible hosts, such as ticks, mosquitoes, flies, spiders or lice? You would be amazed at the sheer number of different viruses that live happily in those animals.
Researchers in China did just that and discovered that, among these viruses, were several unknown variants of the Quaranjavirus, a group of viruses that is part of the Orthomyxoviridae[1]. Until that moment in time the Quaranjavirus consisted of Johnston Atoll Virus, Quaranfil Virus, Lake Chad Virus, Tyulek Virus and Wellfleet Bay Virus.

The researchers needed to be creative to name these thirteen novel viruses: Jinshan Fly Virus 1 (in true flies), Jiujie Fly Virus (in horse flies), Sanxia Water Strider Virus 3 (in water striders), Shangao Insect Virus 4 (in several insects), Wuhan Louse Flu Virus 3 (several insects), Wuhan Louse Fly Virus 4 (in several insects), Wuhan Mosquito Virus 3 (in mosquitoes), Wuhan Mosquito Virus 4 (in mosquitoes), Wuhan Mosquito Virus 5 (in mosquitoes), Wuhan Mosquito Virus 6 (in mosquitoes), Wuhan Mosquito Virus 7 (in mosquitoes), Wuhan Mothfly Virus (in several insects) and the Wuchang Cockroach Virus 2 (in cockroaches).

The closed relative of all these viruses – except one – is the Johnston Atoll Virus. The only exception is the Wuchang Cockroach Virus 2 and that one is related to the Influenza C Virus. That is all pretty worrysome.

[1] Ci-Xiu Li et all: Unprecedented genomic diversity of RNA viruses in arthropods reveals the ancestry of negative-sense RNA-viruses in eLIFE – 2015. See here (pdf).

Bourbon Virus

Researchers have identified a previously unknown virus, thought to be transmitted by ticks or other insects, that led to the death of a farmer in Kansas (USA) during the summer of 2014. The first symptoms were fever, low red and white blood cell counts, elevated liver enzymes and loss of appetite. The illness was fast-moving and severe, causing lung and kidney failure, and shock. The man, previously healthy, died after about only 10 days in the hospital[1].

The newly discovered infectious agent has been named the Bourbon virus, which has been named after Bourbon County, part of Kansas City, where the patient had lived. Laboratory tests finally determined that the virus belongs to the ever expanding family of Orthomyxoviruses.
The Bourbon virus possesses a genome similar to that of related viruses in Eastern Europe, Africa, and Asia. Dr. J. Erin Staples, a medical epidemiologist at the C.D.C. laboratory in Fort Collins, Colo. She said the virus was part of the thogotoviruses, a subdivision of the Orthomyxoviruses. Scientists think the Bourbon Virus has been around for some time and suspect there have possibly been milder cases, but information is still scarce.

What this discovery demonstrates is that the Orthomyxoviruses, a family that also harbours the Influenza viruses, is seemingly expanding at a hightened pace. The Bourbon Virus is deadly, even for healthy individuals.

The Bourbon Virus belongs to the Thogotoviruses and that makes it a direct relative of the influenza viruses because all are part of the larger family of Orthomyxoviruses. The genus Togotoviruses has eigth known distinct members: Thogoto Virus, Dhori Virus, Araguari Virus, Batken VirusJos Virus, Upolu Virus and Aransas Bay Virus.

[1] Kansas Department of Health and Environment: KDHE and CDC Investigate New Virus – December 22th, 2014. See here.

Wellfleet Bay Virus

Since 1998, cyclic mortality events in common eiders (Somateria mollissima), numbering in the hundreds to thousands of dead birds, have been documented along the coast of Cape Cod, Massachusetts (USA). The virus attacks the liver and gallbladder. Eider ducks collected from these mass die-offs appear healthy and are not emaciated from long illness; they die from liver failure. Detecting the cause of the massacre has proven enigmatic.

Now, research has identified a novel orthomyxovirus, tentatively named Wellfleet Bay Virus, as a potential causative agent of these outbreaks[1].
[Image: blog.momoet.ee]
Analysis of Wellfleet Bay Virus revealed that it is most closely related to members of the Quaranjavirus genus within the family Orthomyxoviridae. The researchers also suggested that the virus might be transmitted by ticks.

Although Wellfleet Bay Virus shows low to moderate levels of similarity to Quaranfil Virus and Johnston Atoll Virus, both members of the Quaranjavirus genus, additional antigenic and genetic analyses demonstrated that it is closely related to the recently identified Cygnet River Virus from South Australia, suggesting that Wellfleet Bay Virus and Cygnet River Virus may be geographic variants of the same virus.

Although the identification of Wellfleet Bay Virus in part may resolve the enigma of these mass mortality events, the details of the ecology and epidemiology of the virus remain to be determined. As is the potential effect of this virus on humans.

[1] Allison et al: Cyclic avian mass mortality in the northeastern United States is associated with a novel orthomyxovirus in Journal of Virology – 2014

Influenza A(H5N8) Virus in Europe

We always maintained that the Influenza virus is a very versatile virus. So, when a novel version emerged in South Korea last spring, red flags were raised. Influenza A(H5N8) Virus spread to dozens of poultry farms, resulting in the destruction of more than 13 million birds.

While no human infections were reported, this virus is a close cousin of the lethal Influenza A(H5N1) Virus, which has a long history of occasionally infecting humans, often with tragic results. South Korea did report detecting Influenza A(H5N8) antibodies in dogs.See here.
The infections seemed to be limited to South Korea and some politicians went back to sleep, certain that the problem was resolved.

Then, in November 2014, Germany unexpectedly reported an outbreak of highly pathogenic avian Influenza A(H5N8) Virus in turkeys in North East Germany. Increased mortality was observed in a number of the 31,000 bird on the premises. All these birds were culled.

A few weeks later, authorities in The Netherlands reported an outbreak Influenza A(H5N8) Virus in poultry. All 150,000 hens were culled. And just a few days after that report, British authorities confirmed yet another case of Influenza A(H5N8) Virus in a duck breeding farm in Yorkshire. Then several other sporadic outbreaks were reported in Netherlands.

Autumn is the season for increased wild bird migration, especially waterfowl, as well as seasonal poultry production (read: turkeys reared for Christmas) and therefore it poses an increased risk of incursion of any Influenza virus into the poultry sector through direct and indirect contact with wild birds. No wonder then that German investigations found Influenza A(H5N8) Virus in common teals (Anas crecca) and their Dutch counterparts found the virus in Eurasian wigeons (Anas penelope). Both species migrate from Siberia and pass over Great Britain, The Netherlands and Germany en route to sunny Africa.

Influenza A Virus in Vultures

Vultures are having a hard time surviving in the wild. They are more and more in danger of extinction because of the indiscriminate use of diclofenac and other NSAIDS. See here and here.

But research have also indicated that sevaral species of vultures can be infected with Influenza A viruses.
[Image: William Warby]
Analysis of hooded vultures (Necrosyrtes monachus) in Burkina Faso showed infection with highly pathogenic Influenza A(H5N1), a subtype of Influenza that was initially found in Nigeria and later in other African countries[1]. Later that year, seven other African countries have reported Influenza A(H5N1). Infections. Research indicated that these human infections with Influenza A(H5N1) in Africa emerged outside of Africa and seemed to have followed the east African/west Asian and Black Sea/Mediterranean flyways of migratory birds[2].

Hooded vultures feed mostly from carcasses of dead animals but they also prey on dead and dying birds. These vultures are typically unafraid of humans, and frequently gather around habitation. It is sometimes referred to as the 'garbage collector' by locals.

We can therefore safely assume that the hooded vultures  are potential vectors or sentinels of influenza A viruses.

[1] Ducatez et al: Genetic characterization of HPAI (H5N1) viruses from poultry and wild vultures, Burkina Faso in Emerging Infectious Diseases – 2007
[2] Ducatez et al: Molecular and antigenic evolution and geographical spread of H5N1 highly pathogenic avian influenza viruses in western Africa in Journal of General Virology – 2007

European Seals Dying of Influenza A(H10N7)

In 2011 seals in New England (USA) died, which was eventually linked to an infection with Influenza A(H3N8) Virus. See here. Before it appeared in seals, the Influenza A(H3N8) Virus was known as an avian adapted virus and was commonly found in the digestive and respiratory tracts of birds: alpha 2,3 receptor cells. But in these seals the virus had adapted to the mammalian alpha 2,6 receptor cells, the type also found in the human upper respiratory tract[1].

In recent weeks there have been reports of large die offs of seals in Denmark and Germany, and it was determined that a combination of an infection with avian Influenza(H10N7) Virus, pneumonia, and bacterial infections were behind these deaths[2].
[Image: www.emeral-vision.com]
Professor Lars Erik Larsen of the Section of Virology at the National Veterinary Institute explains: 'The Influenza virus weakens the seals, thus becoming more susceptible to other infections which may contribute to the deterioration of the disease and possibly lead to seals dying. Initially, the seals probably got the flu by being in contact with birds or their droppings.'

Nothing to worry about, you might say at this point. Some seals might be dying, but there are some worrying aspects to this news, because Influenza A(H10N7) Virus is also able infect humans. Some cases of such an infection appeared from countries like Egypt (2004) (pdf here) and Australia (2012)[3]. Given its limited history of infecting humans, and the mild symptoms it has provoked, Influenza A(H10N7) Virus seems an unlikely candidate to cause a serious epidemic threat.

But, like all Influenza A viruses, Influenza A(H10N7) has the ability to drift, mutate, or reassort with other influenza viruses and – over time - continually re-invent itself.

[1] Anthony et al: Emergence of Fatal Avian Influenza in New England Harbor Seals in mBio – 2012
[2] DTU Veterinærinstituttet: Sæler fra flere områder af Danmark smittet med influenza. See here.
Arzey et al: Influenza virus A (H10N7) in chickens and poultry abattoir workers, Australia in Emerging Infectious Diseases - 2012

Tyulek Virus

And again a new virus will be added to the ever expanding family that also harbours the Influenza viruses. The Tyulek Virus was first isolated from some ticks, Argas vulgaris, collected from the burrow biotopes in multispecies birds colony in the Aksu river floodplain near a village called Tyulek, situated in the northern part of the Chu Valley, Kyrgyzstan.

Recently, the Tyulek Virus was assigned to the Quaranfil group. The Tyulek Virus is thus directly related to the Johnston Atoll Virus,the Lake Chad Virus and the Quaranfil Virus. It is therefore a novel member of the Quaranjavirus that is itself grouped within the Orthomyxoviridae family[1].
The complete genome sequence of the Tyulek Virus was determined. Comparison shows a close relationship (70-80%) between the Tyulek Virus and the other three Quaranjaviruses.

Which means that the Orthomyxoviridae family keeps expanding and its danger of spreading and mutating grows too.

[1] L’vov et al: Taxonomic status of the Tyulek virus (TLKV) (Orthomyxoviridae, Quaranjavirus, Quaranfil group) isolated from the ticks Argas vulgaris Filippova, 1961 (Argasidae) from the birds burrow nest biotopes in the Kyrgyzstan in Voprosy Virusologii - 2014

Influenza and the Anti-Vaxxers

Some people have an irrational and delusional distrust of vaccination. Yes,it's true: some vaccinations can have side effects that are, on rare occasions, serious. But, generally, the malady is far worse than the cure.


One of the reasons some people distrust vaccinations is a man called Andrew Wakefield. He claimed that there was a link between (the administration of) the measles, mumps and rubella (MMR) vaccine, and the appearance of autism and bowel disease[1]. His fallacious hypothesis led to a drastic drop in vaccination coverage in the UK and other countries, with a consequent increase in the incidence of measlesand its complications. His paper was so willingly riddled with fraudulent data (the commission found three dozen charges proved, including four counts of dishonesty and 12 counts involving the abuse of developmentally challenged children) that it has eventually been retracted by the editors of The Lancet and Wakefield was struck off the Medical Register in May 2010. He can never work as a doctor again.

More trustworthy research has not been able to find one shred of evidence that vaccination causes autism (or any other illness or disorder). Still, some people continue to see Wakefield as a sort of martyr and they still maintain that the MMR vaccine must cause autism. Why do people rather believe someone who’s a known fraud and not trust honest science?
It probably is some sort of defence mechanism in which controversial behaviours or feelings are justified and explained in a seemingly rational or logical manner to avoid the true explanation, and are made consciously tolerable – or even admirable and superior – by plausible means. How else can you believe in homeopathy? It’s quackery and your brain must know it on a certain rational level, but you explain it away because you want to believe it works.

As a result people put their children in potentially mortal danger by refusing to give them their vaccinations, because they think the tiny bodies of infants are being overwhelmed with too many antigens. However, the antigens in the vaccine schedule has actually decreased over the years (as the vaccines have become more targeted), and the number of antigens children face on a daily basis from the environment vastly outnumber the few additional antigens in vaccines. Which resulted in a surge in pertusis cases in the USA[2].

Even the annual flu-shot is distrusted because some (still) contain Thimerosal, a mercury-containing organic preservative. The reasoning for the Anti-Vaxxers is simple: mercury is a poisonous substance and therefore the flu-shot is specifically aimed at killing you. The FDA have extensively tested Thimerosal and decided it was safe to use at levels far higher than are used these days in vaccines. Most Influenza vaccines do not even contain Thiromersal[3].
I suppose you first have to suffer from a serious bout of Influenza before you start thinking that vaccination isn’t such a bad idea after all.

BTW:  The Human Papillomavirus (HPV) vaccine was given to Australian girls since 2007 and researchers now found that the rate of genital warts in young Australian women decreased by 61 percent, while rates in age and sex groups not covered by the program were unchanged. See here.

[1] Wakefield et al: Ileal-lymphoid-nodular hyperplasia, non-specific colitis, and pervasive developmental disorder in children in The Lancet - 1998
[2] Kahn et al: Case-control study of vaccination history in relation to pertussis risk during an outbreak among school students in The Pediatric Infectious Disease Journal - 2006
[3 FDA: Thimerosal in Vaccines. See here

Influenza A Virus in Ostriches

When we think about the spread of Influenza A viruses in birds, we most often will point to migrating bird as the source of the disease. During their flight over long distances these birds excrete their poo which contains large amounts of viruses. This in turn can infect domestic poultry such as chicken.

There are however other species of birds that are susceptible to the various Influenza A Viruses. We have already mentioned sparrows and penguins, but now reports have been published of two outbreaks in Saudi Arabia of Influenza A Virus in ostriches[1].
The infected ostriches suffered from depression, anorexia and diarrhea. Some were so diseased that they did not survive. The specific viruses responsible for these two outbreaks were sequenced and characterized as Influenza A(H5N1) Virus: A/ostrich/Saudi Arabia/6732-3/2007 and A/ostrich/Saudi Arabia/3489-73VIR08/ 2007 from backyard and commercial flocks, respectively. Further analysis of both isolates revealed that the two viruses belong to a cluster with the Influenza A(H5N1) Virus isolated from falcons and turkeys during 2007 in Saudi Arabia.


Earlier outbreaks of Influenza A viruses in ostriches occured in South Africa. Tests revealed that the animals were infected with Influenza A(H5N2) Virus. The outbreak strains in 2011 had no genetic relationships to the previous 2004 and 2006 Influenza A(H5N2) outbreak viruses[2].

It occurs to me that possibly every mammalian or avian species is at risk of getting infected with the Influenza A viruses and can therefore act as a mixing vessel. New or even slightly changed viruses may unexpectedly appear from every part of the globe.

[1] Ismail et al: Characterization and phylogenetic analysis of a highly pathogenic avian influenza H5N1 virus isolated from diseased ostriches (Struthio camelus) in the Kingdom of Saudi Arabia in Avian Diseases - 2014
[2] Abolnik et al: Molecular analysis of the 2011 HPAI H5N2 outbreak in ostriches, South Africa in Avian Diseases - 2012

Influenza A(H3N2)v Virus in Humans

In the United States, in contrast to the 309 cases reported in 2012, only 19 cases of human infection with a non-seasonal variant of Influenza A(H3N2) viruses were reported in 2013. This particular virus was designated Influenza A(H3N2)v37 and was known to have been circulating in swine.

One virus originating from a human case with onset in 2013 has been fully characterized and is almost identical to Influenza A(H3N2)v viruses isolated from patients in the USA in 2012. In 2013, only 1 person was hospitalized as a result of Influenza A(H3N2)v virus infection and there were no deaths[1].
[Chart by Fred de Vries]

The majority of human cases with influenza A(H3N2)v virus infections have occurred in children and are generally mild and associated with exposure to swine,[2] especially among participants in agricultural fairs during the northern hemisphere’s summer and early autumn months.

A variety of influenza A(H3N2) virus strains are endemic in swine populations in most regions of the world. Depending on geographic location, the genetic and antigenic characteristics of these viruses differ. Human infections with non-seasonal influenza A(H3N2) viruses have been documented in Asia, Europe and North America.[3]

[1] http://www.cdc.gov/flu/swineflu/h3n2v-case-count.htm.
[2] http://www.cdc.gov/flu/swineflu/h3n2v-basics.htm#what-is.
[3] Myers et al: Cases of swine influenza in humans: a review of the literature in Clinical Infectious Diseases - 2007

Influenza Vaccination and Zinc

In the olden days scientific information was only published in scientific journals. News filtered down via newspapers and only then non-medical people could read of the latest scientific news. Now, the Internet delivers virtually all information, true or false, without any context. How would you know with site contains true information? Well, this site for instance.
On countless sites the connection between influenza and zinc is heralded. Zinc is a trace element which means that your body only needs an infinitely small amount of it. Just as all other trace elements, it is important for several functions in your body. Most sites claim that zinc is pivotal for a strong immunity and they are right. What these sites fail to mention is that zinc deficiency is usually due to insufficient dietary intake. In layman’s terms: you do not eat enough healthy foods but that doesn’t happen much in the western world.

It has been hypothesized that micronutrient levels of - amongst others zinc - play a role in the immune response to vaccination. It is also hypothesized that decreasing levels of nutrients would be associated with decreased responses to influenza vaccination. The purpose of a recent study was to determine whether serum zinc levels are associated with influenza vaccine response in adults 65 years or older. Participants in this study included 205 adults 65 years or older who received a influenza vaccine and donated blood samples before and 21 to 28 days after vaccination. Of these, 20% had low serum zinc levels.

After adjusting for age, sex, body mass index, and prevaccination titer., the study showed no association between variations in levels of zinc and influenza vaccine response[1].

Our advice remains: eat healthy and vaccinate yourself against seasonal influenza.

[1] Sundaram et al: Vitamin E, vitamin A, and zinc status are not related to serologic response to influenza vaccine in older adults: an observational prospective cohort study in Nutrition Research - 2014

Influenza A Virus in Camels

About half a century ago the avian Influenza A(H3N8) virus jumped to horses, mutating to the equine Influenza A (H3N8) virus or Influenza A/Equine-2. See here. Then, in 2004, it was reported that this virus again breached a species barrier and was now infecting dogs as canine Influenza A(H3N8). See here.

Influenza A/Equine-2 was first recognized in 1963 as a cause of widespread epidemics and has become endemic in many countries. Mongolia is home to recurring epizootic outbreaks of this particular Influenza A virus. These outbreaks, which occur roughly once a decade, not only impact the lives and economy of nomadic Mongolians, it has the potential of infecting other mammals.

While not as plentiful as horses, the Bactrian camel (Camelus bactrianus) is an important domesticated beast of burden for these nomadic Mongolians, and as such is frequently exposed to both humans and horses. It is also on the critically endangered list and may already be extinct in the wild.
[Image: jamo.mn]
In the fall of 1979 a severe epizootic influenza broke out among Mongolian camels, which turned out to be a reassortant of the recently re-emerged (1977) Influenza A(H1N1) virus (also known as the `Russian flu’), showing that this species of camels was susceptible to at least some strains of influenza.

Anecdotal reports of signs of respiratory illness in Bactrian camels were the reason to take a closer look at these camels and their potential infectious diseases. Nasal swab specimens were collected from seemingly healthy Bactrian camels in Mongolia during 2012. One specimen was positive for influenza A/camel/Mongolia/335/2012(H3N8), which is phylogenetically related to equine influenza A(H3N8) virus and probably represents natural horse-to-camel transmission[1].

[1] Myagmarsukh Yondon, Batsukh Zayat et al: Equine Influenza A(H3N8) Virus Isolated from Bactrian Camel, Mongolia in Emerging Infectious Diseases - 2014

Influenza A(H5N6) is now killing humans too

There are several Influenza A viruses circulating at any given moment on mainland China. Science tries to reassure us by maintaining that there are strains that have a low pathogenicity and just a few that have high pathogenicity.

The mantra is that we needn’t worry too much about those Low Pathogenic Avian Influenza (or LPAI) because, while these viruses may infect people, they ‘only cause mild disease, including conjunctivitis and influenza-like illness'.
In 2013 four types of Influenza A Virus - H7N9, H10N8, H6N1 and H9N2 - infected humans for the first time, all in China. About one-fifth of the 419 cases of Influenza A(H7N9) infections proved fatal. Three people contracted Influenza A(H10N8), while a woman in Taiwan was infected with Influenza A(H6N1) but recovered. One person from Hong Kong was infected with Influenza A(H9N2).

Now a 49-year-old man in the Chinese province of Sichuan has died of Influenza A(H5N6) is the first known human infection of this particular strain in the world. The man had been in contact with dead poultry that had the disease. He died after being diagnosed with acute pneumonia.

Experts consider it an isolated case and the risk of human-to-human transmission very low as no one who had been in close contact with the man had shown symptoms[1]. Chen Ze, a professor at the Shanghai Institute of Biological Products, said "The public do not need to worry too much". But Yuen Kwok-yung, a professor of microbiology at the University of Hong Kong, said: "Nobody knows how pathogenic or transmissible it is in humans as it is a different ball game."

[1] China Daily: Risk low for outbreaks of human H5N6 cases (08 May 2014)

Influenza A(H7N9) 'danger zones' mapped

Now, so-called ‘danger-zones’in Asia which are vulnerable to a new eruption of Influenza A(H7N9) or bird flu have been mapped by scientists. To date this variant of Influenza A has infected 433 people and has killed 62. The study showed that parts of Bangladesh, India and Vietnam could face an explosion of novel cases[1].

Viruses mutate and reassort, they undergo antigenic drift and antigenic shift. They are always a concern because of their unknown potential to spread round the world as a deadly pandemic.
Data from the current Influenza A(H7N9) outbreak was used to build a computer model of other at-risk areas in Asia. It involved mapping 8,000 live-poultry markets and assessing how close together they needed to be to spread the infection.

The map does not show where the virus will end up next, just those areas where conditions are suitable to sustain the virus if it managed to get there. Bangladesh, northern India, the Mekong and Red River deltas in Vietnam and isolated parts of Indonesia and Philippines were identified as at-risk areas. Thailand was not considered a risk zone due to cultural differences, which mean live-poultry markets are not common. Equally noticeable that the whole of China is not equally at risk.

The main use of the maps is to target surveillance, This map can show areas where there is a high chance of the disease flaring up if it arrives.

[1] Gilbert et al: Predicting the risk of avian influenza A H7N9 infection in live-poultry markets across Asia in Nature Communications - 2014

Influenza Virus from 1918 Recreated

The Influenza epidemic of 1918 created havoc amongst the population of the entire world. Designated the Spanish flu it killed an estimated 50 million people. It then went extinct.

But now, scientists at the University of Wisconsin-Madison created the virus anew from fragments of other existing wild bird flu strains. They then mutated the virus to make it airborne to spread more easily from one animal to another.

Influenza viruses circulate freely in wild bird populations. Most remain in chickens, ducks and other birds, but occasionally strains mutate into a form that can infect humans. The Influenza A(H5N1) has killed at least 386 people since 2003, according to WHO figures. The Spanish 1918 flu is thought to have come from birds too.
One of the researchers, Kawaoka, describes[1] how his team analysed various bird flu viruses and found genes from several strains that were very similar to those that made up the 1918 human flu virus. They combined the bird flu genes into a single new virus, making a new pathogen that was only about 3% different from the 1918 human virus.

The freshly made virus – the first of several the team created – was more harmful to mice and ferrets than normal bird flu viruses, but not as dangerous as the 1918 strain. It did not spread between ferrets and none of the animals died. But the scientists went on to mutate the virus, to see what changes could make it spread. Seven mutations later, they had a more potent version that spread easily from animal to animal in tiny water droplets - the same way Influenza spreads in humans.

The work is the latest in a series of controversial studies that have split the scientific community. In an article, one scientist argued that experiments like this could unleash a catastrophic pandemic if a virus escaped or was intentionally released from a high-security laboratory[2].

But, of course, Kawaoka defended the work, saying that critics failed to appreciate the impact of his and others' work on dangerous viruses. "There were discussions on the usefulness of stockpiling H5N1 [bird flu] vaccines until our H5N1 papers were published. Similarly, this paper strongly supports stockpiling anti-influenza drugs. If this is not a 'lifesaving benefit', what is?" he said.

[1] Watanabe et al: Circulating Avian Influenza Viruses Closely Related to the 1918 Virus Have Pandemic Potential in Cell Host and Microbe - 2014
[2] Lipsitch, Galvani: Ethical Alternatives to Experiments with Novel Potential Pandemic Pathogens in PLoS One - 2014