Another flu season is upon us, and for some that means a new seasonal influenza vaccine.
As always, it is important to know the facts, evaluate your own risks and make sure that you make an informed decision. I myself have been exposed to some misinformation already, even thought the amount of noise is nowhere close to the levels from the last year, when we were in the midst of the "swine" flu (H1N1) pandemic.
The most prevalent piece of misunderstanding comes from the fact that this year's seasonal flu vaccine has the H1N1 component already included (see CDC: Vaccine Selection for the 2010–2011 Influenza Season), which was not the case last year (that's because last year's vaccine components were selected long before the H1N1 pandemic appeared). What I keep hearing is that this component is the same "untested" vaccine that we were using last year, which is partially true: it is the same H1N1 strain. However, one can not get any better testing for the vaccine strain than what we got last year, with tens of millions receiving the H1N1 shot, and almost no serious side effects reported by the CDC (discussion here: Vaccine Safety).
What is really worring from my point of view is the fact that the misinformation about flu vaccines, and about vaccines in general, comes not from regular, untrained people like myself. The real problem are professionals on the fringe, who for various ideological reasons still buy into the whole conspiracy theory, and claim "facts" about vaccines that are not true (like mercury in childhood vaccines) to scare people from getting the shots they might need to save their lives.
Some good resources from CDC to help you make up your mind: