Virology News
Follow
Find tag "H1N1"
28.0K views | +18 today
Virology News
Topical news snippets about viruses that affect people. And other things.
Curated by Ed Rybicki
Your new post is loading...
Your new post is loading...
Scooped by Ed Rybicki
Scoop.it!

Potential for H3N2 influenza pandemic

Potential for H3N2 influenza pandemic | Virology News | Scoop.it

The 2009 swine-origin H1N1 influenza, though antigenically novel to the population at the time, was antigenically similar to the 1918 H1N1 pandemic influenza, and consequently was considered to be [ldquo]archived[rdquo] in the swine species before reemerging in humans. Given that the H3N2 is another subtype that currently circulates in the human population and is high on WHO pandemic preparedness list, we assessed the likelihood of reemergence of H3N2 from a non-human host. Using HA sequence features relevant to immune recognition, receptor binding and transmission we have identified several recent H3 strains in avian and swine that present hallmarks of a reemerging virus. IgG polyclonal raised in rabbit with recent seasonal vaccine H3 fail to recognize these swine H3 strains suggesting that existing vaccines may not be effective in protecting against these strains.


Vaccine strategies can mitigate risks associated with a potential H3N2 pandemic in humans.

Ed Rybicki's insight:

No-one think of H3N2...except, as it happens, these folk - who have shown quite convincingly that circulating strains of H3N2 in birds and pigs would be quite capable of avoiding vaccine-conferred immunity, and potentially of causing a pandemic, if they reassorted with human-infecting viruses.  

 

I can't help but feel that there are several ticking influenza pandemic time bombs out there...H5N1, H7N9, and now H3N2.

more...
No comment yet.
Rescooped by Ed Rybicki from Virology and Bioinformatics from Virology.ca
Scoop.it!

Easy Jump for H5N1 from Bird to Mammal

Easy Jump for H5N1 from Bird to Mammal | Virology News | Scoop.it
Hybrid viruses derived from an H5N1 bird flu strain can infect guinea pigs through the air.
Ed Rybicki's insight:

It is rather concerning that these guys did NOT have to make HA mutations to get their viruses easily transmissible - they just to make reassortants with H5N1 and H1N1pdm viruses.  As could happen in pigs or poultry anywhere both viruses occur....

 
more...
No comment yet.
Scooped by Ed Rybicki
Scoop.it!

Special Report: How vaccine scares cast shadows over science

Special Report: How vaccine scares cast shadows over science | Virology News | Scoop.it

...

His story underscores an increasingly tough challenge for scientists balancing compelling data with public concern over vaccines and their side effects. Treatments which stimulate immunity to disease are highly controversial. In the past couple of decades - especially after a British doctor made now-discredited claims linking the measles-mumps-rubella (MMR) vaccine to autism - the field has become even more charged. After the false alarm sounded by British doctor Andrew Wakefield, some scientists say they are more hesitant to credit reports of potential side effects from vaccines.

 

Ed Rybicki's insight:

A well-balanced article about just how difficult it can be to deal with real side effects of vaccines, in a climate where disinformation is frequently very stridently disseminated.

 

However, I have previously highlighted in this forum that H1N1pdm flu infection itself is associated with narcolepsy - a fact which seems to be ignored when people discuss how the vaccine causes / is associated with it.

more...
No comment yet.
Scooped by Ed Rybicki
Scoop.it!

Antigenic Drift of the Pandemic 2009 A(H1N1) Influenza Virus in a Ferret Model

Antigenic Drift of the Pandemic 2009 A(H1N1) Influenza Virus in a Ferret Model | Virology News | Scoop.it

Infection with influenza virus leads to significant morbidity and mortality. Annual vaccination may prevent subsequent disease by inducing neutralizing antibodies to currently circulating strains in the human population. To escape this antibody response, influenza A viruses undergo continuous genetic variation as they replicate, enabling viruses with advantageous antigenic mutations to spread and cause disease in naïve or previously immune or vaccinated individuals. To date, the 2009 pandemic virus (A(H1N1)pdm09) has not undergone significant antigenic drift, with the result that the vaccine remains well-matched and should provide good protection to A(H1N1)pdm09 circulating viruses. In this study, we induced antigenic drift in an A(H1N1)pdm09 virus in the ferret model. A single amino acid mutation emerged in the dominant surface glycoprotein, hemagglutinin, which had a multifaceted effect, altering both antigenicity and virus receptor specificity. The mutant virus could not be isolated using routine cell culture methods without the virus acquiring additional amino acid changes, yet was fit in vivo. The implications for surveillance of circulating influenza virus are significant as current assays commonly used to assess vaccine mismatch, as well as to produce isolates for vaccine manufacture, are biased against identification of viruses containing only this mutation.

 

Influenza virus graphic by Russell Kightley Media 

Ed Rybicki's insight:

There is a rather disturbing result in this paper: that is, that the mutation in the H1N1 HA that emerged in serial ferret transfers that was responsible for antigenic drift, resulted in a virus that could NOT be cultured by routine methods despite being quite happy in ferrets.  In fact, adapting the virus to culture meant it accumulated MORE mutations, meaning the thing they got out by "current assays" was NOT the same thing that was causing disease.

 

This is worrying for a number of reasons, not least of which is that informed decisions on probable vaccine efficacy are made as a result of such assays - and the vaccines themselves, in some cases.  And if what these decisions are based on is incorrect...?

 

Time for some better science here, people - like next-gen sequencing rather than isolation as a measure of what is causing disease!

more...
No comment yet.
Scooped by Ed Rybicki
Scoop.it!

Who can catch which flu?

Who can catch which flu? | Virology News | Scoop.it
Imgur is used to share photos with social networks and online communities, and has the funniest pictures from all over the Internet.
Ed Rybicki's insight:

Excellent graphic!

more...
No comment yet.
Scooped by Ed Rybicki
Scoop.it!

A geographic analysis of population density thresholds in the influenza pandemic of 1918-19

A geographic analysis of population density thresholds in the influenza pandemic of 1918-19 | Virology News | Scoop.it

Geographic variables play an important role in the study of epidemics. The role of one such variable, population density, in the spread of influenza is controversial.

Prior studies have tested for such a role using arbitrary thresholds for population density above or below which places are hypothesized to have higher or lower mortality. The results of such studies are mixed.

The objective of this study is to estimate, rather than assume, a threshold level of population density that separates low-density regions from high-density regions on the basis of population loss during an influenza pandemic. We study the case of the influenza pandemic of 1918--19 in India, where over 15 million people died in the short span of less than one year.

 

Pandemic recombinant influenza virus graphic from Russell Kightley Media

Ed Rybicki's insight:

This is an interesting paper, because it is one of the ONLY ones I have ever seen that analyses ANYTHING to do with the 1918 H1N1 pandemic, that comes from a developing country.  Moreover, it makes what I think is possibly quite a valuable contribution to "health geographics", especially for high-denisty low-income populations.

I also note that 15 MILLION PEOPLE were estimated to have died in India ALONE: this is close to the old estimate for the WORLD total (20 million), which was revised upwards to 50-100 million after developing country stats were taken into account, in the late 1990s.

Makes you wonder what a new version might do....

 

 

more...
No comment yet.