Saturday, 14 February 2015

Flu jab is not a 'waste of time'

Crabsallover comment: As the Public Health England Press Release says 'The research, based on the results from 1,314 patients presenting in primary care across the UK, found that vaccine effectiveness in preventing laboratory confirmed influenza was estimated to be 3% overall. This compares to approximately 50% vaccine effectiveness that has typically been seen in the UK over recent years.'
PHE also says" In the UK, influenza A(H3N2) is the predominant subtype circulating this season to date, and H3N2 viruses similar to A/Texas/50/2012 are the strains that the vaccine currently protects against. Analysis conducted by PHE has shown a large proportion of flu viruses circulating have shown evidence of either antigenic or genetic drift from A/Texas/50/2012, and were similar to another H3N2 strain; A/Switzerland/9715293/2013. The A/Switzerland/9715293/2013 strain has been recommended for inclusion in the southern hemisphere influenza vaccine to be used in 2015.'

'The World Health Organization monitors influenza globally and each year recommends the strains of flu virus that should be included in the flu vaccine for the forthcoming flu season. It takes from February through to August / September to produce sufficient quantities of the flu vaccine. If a change in the virus is detected once production has started it is not possible to change it.  Throughout the last decade, there has generally been a good match between the strains of flu in the vaccine and those that subsequently circulate, so it’s crucial that these results do not discourage people in at-risk groups from having flu vaccination now, or in the future.'

Interesting comparison of what is in seasonal H3N2 flu vaccines.
Friday February 6 2015
Vaccine makers are locked in an 'arms race' with mutating strains
This year’s flu jab may still protect against other strains
“Flu jab given to millions is 'useless',” and "Flu jab is a waste of time," are the irresponsible headlines in The Daily Telegraph and the Daily Mail.
While recent research shows that the currentseasonal flu vaccine only has 3% protection against the main circulating strain – A(H3N2) – in adults, it can still protect against other strains.
Both papers also ignore the fact that another version of the flu vaccine, in the form of a nasal spray designed forvulnerable children, is also available.
Discouraging parents of vulnerable children from getting vaccinated could increase the risk of serious childhood illnesses and possible hospitalisation.

Why is the flu vaccine not working?

There are many strains of the influenza virus and each one can mutate. It takes time to develop and produce vaccines against them. Global surveillance is used to predict which strains are likely to be circulating the following winter, and in February the World Health Organization (WHO) announces which strains the flu vaccine should cover. Last year, it decided to cover three flu varieties:
  • Influenza A (H1N1), also known as “swine flu"
  • Influenza A (H3N2)
  • Influenza B
In March, the WHO Global Influenza Surveillance and Response System detected a new strain of influenza A (H3N2), but this was too late to change the production of the vaccine.
It was also not known whether this particular strain would be the predominant strain this winter, which it has been, and so the vaccine is not effective against it.

‘A Jack Bauer car chase’

“Trying to predict which seasonal flu vaccine to produce each year must be a bit like a Jack Bauer [hero of the TV thriller series '24'] car chase in Los Angeles.
“At any intersection, the fugitive has three choices of direction. Bauer can’t catch up, and he doesn’t know the ultimate destination, so he has to try to guess the likeliest turns, and place his limited team in side streets where they’re most likely to block the fugitive, to slow him down or capture him. Even with Jack Bauer’s experience, this is bound to prove somewhat hit and miss.”
Dr Michael Skinner, Reader in Virology, Imperial College London (and fan of ‘24’).

How effective is it?

The vaccine is effective against the other strains of influenza, but not the new strain of influenza A (H3N2). The mid-season vaccine effectiveness rate is just 3.4%. Vaccination against this new strain and other possible mutations will be considered at the WHO meeting this February for next winter.

Reactions to the news

Dr Michael Skinner, Reader in Virology, Imperial College London said: “The current type of seasonal influenza vaccine is, at the moment, the best we have. Annually it saves tens of thousands of lives. Unusually, but not uniquely, this year one (H3N2) of the four targeted viruses ‘drifted’ (mutated) in an unanticipated direction after the vaccine was formulated for production, so that the vaccine offers little protection against the drifted H3N2.
"Even so, the vaccine still protects against the other three components (pre- and post-2009 H1N1 and B). And it does at least stop the virus drifting back along the path that had been predicted. To describe it as ‘useless’ would be misguided.”

Should you still get the jab?

The other strains can still cause infection so the vaccine is still recommended for pregnant women, people aged over 65 and those with any of the following conditions:

When to visit your GP

If you are otherwise fit and healthy, there is usually no need to visit your GP if you have flu-like symptoms.
The best remedy is to rest at home, keep warm and drink plenty of water to avoid dehydration.
You can take paracetamol or ibuprofen to lower a high temperature and relieve aches.
If you are in any of the high risk groups listed above then you should visit your GP.
Depending on your circumstances, your GP may recommend a short course of antiviral medication, such as Tamiflu (oseltamivir). 
Antivirals are not used for everyone with flu because this would lead to further mutations in the viruses and drug resistance, making them ineffective.
If you suspect you have the flu it is important to take steps to prevent it spreading; especially to one or more of the vulnerable groups listed above.
  • make sure you wash your hands regularly with soap and water
  • clean surfaces such as your keyboard, telephone and door handles regularly to get rid of germs
  • use tissues to cover your mouth and nose when you cough or sneeze
  • put used tissues in a bin as soon as possible
Analysis by Bazian. Edited by NHS Choices. Follow Behind the Headlines on Twitter. Join the Healthy Evidence forum.
Analysis by Bazian
Edited by NHS Choices
reposted (unedited) from:
crabsallover highlightskey pointscomments / links.

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