No vaccine is completely without risk. I don't know of anyone who claims that they are. The issue is, which is greater: the risk of the vaccine or the risk of the disease?
Choosing not to vaccinate is not choosing to take no risk -- it is simply choosing to take a different risk. (Hat tip: Paul Offit.)
Based on previous pandemic flu outbreaks and experience with previous flu shots, the numbers are:
- Serious complications caused by the flu shot occur in about 1 per million people vaccinated. By "serious," I mean severe neurological injury or anaphylactic allergic reaction.
- Non-serious complications caused by the flu shot (such as redness of the eyes, mild fever, and localized soreness at the injection site) occur in about 1 in 10 people vaccinated. The symptoms usually last 1-2 days, though occasionally persist longer.
- The risk of Guillain-Barre syndrome (the neurological disorder most commonly associated with the flu shot) in people who do not get a flu shot is also about 1 per million people.
- Death due to complications of the flu are estimated to have occurred in about 1000 per million people who became ill in previous pandemics.
It is definitely, absolutely, 100% your right to not put anything into your (or your child's) body if you do not want it there. That is a fundamental principle that I think must be honored under virtually all circumstances.
I am not telling anyone what to do -- I simply wish to make evidence-based facts available so that people can make up their minds based on good information. This evidence comes from well-designed, high-quality studies that have been ongoing as long as this particular vaccine has been available.
The safety testing for the H1N1 shot was actually not abbreviated compared to regular seasonal flu shots. The part that was skipped was the initial step where they look at the circulating flu strains in the spring and try to determine which strains will cause problems the following year so that they can be included in the vaccine. With H1N1, they knew exactly which strain to put into the vaccine, so this step was unnecessary. The rest of the safety testing was the same as every year (at least in Canada), which is why the H1N1 vaccine is coming out late.
The only real difference between the H1N1 shot and the regular seasonal flu shot is the addition of an adjuvant. The adjuvant, which is made from things like vitamin E, fish oil and water, is there because it boosts one's immune response to the vaccine so that you can get a lot more doses out of the same amount of material. At the beginning of the manufacturing process, it was not at all clear that enough vaccine could be made to protect the population, which is why they added the adjuvant. The adjuvant has never been used in North American flu shots before because it's never been needed; it's been used for years in flu shots in Europe, and in other vaccines in North America, and has a very good safety record.
The non-adjuvanted vaccine is going to be available for pregnant women, hopefully soon; this is being done because although there's absolutely no evidence to suggest it's harmful in pregnancy, some people feel there is not enough evidence of safety either. This is being done, appropriately in my opinion, out of an abundance of caution.
We can't wait for long-term studies of flu vaccines because by the time the data is available, it's too late -- the virus has done it's thing and moved on to its next version. So we have to go with what we've got right now, based on what's going on in other countries now and on past experience with other flus (pandemic and not) and vaccines. It's entirely possible that H1N1 will fizzle out and we'll look back in the spring and wonder what we were worried about, but so far it looks like H1N1 is coming back pretty aggressively and it would be irresponsible from a public-health perspective to take a "let's see what happens" approach. We do not have a crystal ball to tell us whether this flu is "The Big One" or not. I'm not exaggerating to scare people here -- influenza pandemics can wipe out enormous numbers of people, even with modern sanitation, nutrition, etc.
There is no really effective treatment for influenza. Tamiflu is somewhat helpful but far from a miracle drug, so all that can really be done for someone with the flu is supportive care -- for most, this just means fluids and rest but for those who are hardest hit, it means ventilators and intensive care. And the concern is that more people than with most flus have been in the "hardest hit" group.
This is why the H1N1 vaccine is being offered to everyone.




