Originally Posted by Shiloh
Fears over mutating swine flu virus that could render vaccine useless
By Daily Mail Reporter
Last updated at 12:04 AM on 9th January 2011
A research team has hurriedly been re-formed to investigate whether the swine flu virus has started to mutate in a way that will render the vaccine ineffective.
Senior Government scientists have already discovered slight genetic mutations in the H1N1 virus.
They are checking whether this is causing some people to be more severely affected, although there is no evidence at this stage to suggest the changes would stop the vaccine working or prevent the anti-viral drug Tamiflu from being effective...
From last week Eurosurveillance report: http://www.eurosurveillance.org/View...rticleId=19760
Influenza A(H1N1)2009 isolates characterised to date, in samples from the community, hospitalised patients and fatal cases, are antigenically homogeneous and similar to the A(H1N1)2009 virus included in the 2010/11 seasonal influenza vaccine, A/California/7/2009.
Only minor genetic drift has been noted in influenza A(H1N1)2009 viruses circulating in 2010 compared with the earliest isolates in April 2009, and this observed genetic diversity has been consistent with expected patterns of virus evolution (...).
Phylogenetic analysis shows that HA sequences from nine fatal and four severe cases in the UK in 2010 were interspersed with sequences from mild cases in 2010 from the UK and elsewhere.
All UK 2010 viruses cluster in two main branches, characterised by either E374K with additional mutations in minor subclusters such as D97N, S185T, S451N and N125D, some of which have been recently described , or by A134T and S183P, with additional substitutions such as N441K, R509M and V527I.
Almost all viruses from winter 2010 analysed to date from fatal and non-fatal cases had 222D in the HA gene (39/41).
Preliminary analyses from a limited number of whole genome sequences including some from fatal cases, indicate that these are consistent with observations from seasonal influenza and from the first and second waves of the recent pandemic: so far no unique mutations have been associated with severe or fatal cases of influenza A(H1N1)2009, but further comprehensive analysis is required.
Between October and December 2010, antiviral resistance monitoring was undertaken on 156 community and 159 hospital isolates.
Six cases of oseltamivir resistance associated with the H275Y mutation in the neuraminidase (NA) gene have been detected.
Only one of these cases has had known exposure to oseltamivir, Two of them have been identified from community surveillance of uncomplicated infections, three cases have been detected before treatment in individuals hospitalised with underlying risk factors, and the sixth case has been detected after oseltamivir treatment in a hospitalised individual.
G_MICHIELI (aka IRONOREHOPPER)