Using mathematical modelling, the authors discuss the potential population - level benefits that a universal vaccine would offer over
conventional seasonal vaccines.
«The whole infrastructure required for the preparation
of seasonal vaccines has enormous disadvantages,» remarks Walter Fiers, a molecular biologist at Ghent University in Belgium.
«For the current H3N2, we don't have such studies, so I can't tell you right now the degree the
current seasonal vaccine will protect against the H3N2 virus,» Fukuda says.
Total vaccine supply will depend on several other unknowns, including whether 15 micrograms of antigen is enough — as is the case
with seasonal vaccine — and whether one or two shots are needed.
New results from a study performed at the University of Helsinki suggest that genomic information from circulating influenza viruses can help in producing more
efficient seasonal vaccines.
Instead of putting your faith in the new H1N1 vaccine, he recommends getting a
regular seasonal vaccine — at least at first.
Kieny said that for reasons that aren't fully understood, vaccine companies that use eggs to grow vaccine viruses get yields of only 25 % to 50 % of those obtained during the production
of seasonal vaccine.
Universal vaccines that protect against multiple strains of influenza virus at once could offer key population - level benefits over
conventional seasonal vaccines, according to a new study published in PLOS Computational Biology.
The Centers for Disease Control and Prevention recommends that everyone 6 months and older get
the seasonal vaccine to protect yourself and those around you.
Researchers and health workers save lives by routinely rolling out
seasonal vaccines and deploying drugs to fight the virus and its secondary infections.
Do
these seasonal vaccines have certain disadvantages?
Vaccination programmes begin in the US and Europe, but many healthcare workers are reluctant to have the vaccine, even though it is virtually identical to
the seasonal vaccines used in previous years, which have a good safety record.
It's also possible that the swine flu strain could be added to next year's
seasonal vaccine.
The H3N2 used in
the seasonal vaccine is what's known as the Brisbane subtype.
Although the world's attention is focused on the novel H1N1 virus causing the swine flu pandemic, H3N2, a seasonal strain of influenza, has popped up in many East Asian countries — and some variants in circulation may outfox
the seasonal vaccine in use.
On a related note, Schuchat addressed a report from Canada that showed
the seasonal vaccine increased the risk of becoming infected with the swine flu virus and one from Mexico that showed precisely the opposite finding.
Typically, H3N2 moves from East Asia to Europe and the United States, but Shu said it is too soon to know whether the Perth - like subtype in circulation will make major inroads in the West or reduce the effectiveness of
the seasonal vaccine.
She noted, too, that about 60 % of Americans who CDC recommends should receive
the seasonal vaccine opted not to take it this year.
Shu noted that the center has no data to estimate the efficacy of
the seasonal vaccine against this subtype.
The strain that the U.S. Food and Drug Administration chose for
the seasonal vaccine did indeed closely match the viruses that sickened people.
The agency approved the vaccines with scant clinical data, relying instead on the same «strain change» rules that allow manufacturers to change
the seasonal vaccine without conducting human studies.
«Successful antagonists, following clinical trials for safety and efficacy, could be incorporated into
the seasonal vaccine as a way of enhancing responses.
Growing vaccine viruses in high - yield cell culture should improve the ability of
seasonal vaccines to protect against influenza A and B because vaccine viruses grown in mammalian cell culture are less likely to mutate compared to those grown in eggs.