February 18, 2010

H1N1 Strain To Be Included In New Seasonal Flu Vaccine

The World Health Organization (WHO) recommended on Thursday that this year's seasonal flu vaccine in the northern hemisphere should include protection against three strains, including the pandemic H1N1 virus.

WHO's flu expert Keiji Fukuda said the composition, announced after a four-day meeting of experts, means H1N1 swine flu vaccine still held by drugmakers in bulk form may be used for part of the seasonal flu vaccine mix for autumn/winter 2010/2011.

However, some people's reluctance to receive the shot has some countries, including Germany, France and the United States, cutting back their orders of the H1N1 flu shot. The fact that people needed only one dose, not two, also contributed to oversupply.

Fukuda told reporters that the inclusion of the H1N1 pandemic virus in the influenza vaccine does not signal that the pandemic is over.

"This virus is expected to be a significant threat to people as we go into the fall and winter period," he said.

He added that young people, especially those with chronic medical conditions, and pregnant women continue to be at higher risk of infection and viral pneumonia from the H1N1 virus.

Fukuda said the WHO's emergency committee of influenza experts will meet on February 23 to evaluate whether the world is moving out of the pandemic, but the H1N1 virus is expected to remain the dominant virus circulating worldwide regardless.

"The post peak period means that we continue to be in a pandemic," Fukuda said. The end of a pandemic is "more of a tailing off phenomenon."

He explained that the H1N1 vaccine component held by pharmaceutical companies in bulk form -- but not that already put into syringes or vials -- may be used for the seasonal vaccine mix.

Fukuda told Reuters after a public WHO session attended by drug companies that if countries have the vaccine strain which is already made up and can be used, then they're ahead of the game.

H3N2 -- which like H1N1 is a type of influenza A -- and influenza B are the other recommended vaccine strains.

National health authorities would have to decide whether to combine the three strains into a single "trivalent" shot, offer three separate vaccines, or use a separate H1N1 shot and combine the other two in one shot," he said.

Fukuda said he believes a trivalent vaccine would make sense for many countries.

Fukuda said some 200 million people have received the H1N1 pandemic vaccine so far, but there was no reason to suggest getting the trivalent vaccine would pose any problems for them.

GlaxoSmithKline and Sanofi-Aventis and other vaccine makers need the WHO's vaccine guidance to start formulating shots for the northern hemisphere's 2010/11 mix. The flu season usually begins around November.

Pandemic H1N1 flu may well return in the autumn in the form of seasonal flu, according to Meirion Evans, chair of the Health Protection Committee at the UK Faculty of Public Health.

She said people who suffered from pandemic H1N1 flu or who have had the pandemic vaccine will already have some immunity.


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