Flu Vaccine Less Effective

The flu vaccine, which is generally very good at preventing disease, is formulated 6-12 month before flu season, and is based on the best guess of researchers and what viruses are circulating in the far East.

The flu virus is composed of several strands of RNA (like DNA), and there are up to about 12 different variations of each strand. Some combinations can result if a more severe strain (like Bird Flu), some in a more contagious but less dangerous variety. It is when all factors combine to make a potent virus which spreads more easily (as in 1918) that we have a dangerous epidemic.

This is one of the reasons we need an annual vaccine; to account for changes in the virus. This years "guess" by researchers was less accurate than usual. The virus that was predominating in September of this year was found to be different from the H3N2 strain used in the vaccine (created in February). The strain this year is a slightly different H3N2 variety; but is a potent variety that may be associated with more severe illness.

The CDC recommends that anti-viral medications (such as Tamiflu) be used early in the diagnosis; even before confirmation cultures are back, especially in high risk individuals. If you fall into that group seek medical care as early as possible if you think you have the flu. You can check this web site to help you make that decision.

http://www.cdc.gov/flu/about/qa/testing.htm