It seems like the flu shot is a really good idea on the surface, because who wouldn’t want a little pre-immunity! However, as it turns out, due to the nature of the influenza virus, you may not be getting the protection advertised.
Here’s the short answer: WIth any medical intervention, you have to weight the costs, as well as the benefits to make a good choice. Flu shots are no different. The information available regarding the flu is muddy at best with conflicting statistics. Even the CDC (Center of Disease Control) states on their website that, “[The]CDC does not know exactly how many people die from seasonal flu each year.” So if we don’t know how many people die from flu, how do we come up with effective measures for successful medical intervention? The reason the CDC doesn’t know for sure is because of lack of reporting procedures in the U.S. There are many things that cause respiratory illnesses, and deaths from influenza viruses are not listed as “cause of death”, since it would require a lab test to know for sure. This would be very expensive for hospitals to do, so what happens instead is they get their estimates from statistical modeling based on all respiratory illness related deaths during flu season and not real data.
Currently, there is no way to predict what virus strain will be around in any given flu season until it is already here. This is why some years flu shots are useless and other years more effective. Every year the World Health Organization makes a recommendation of what three flu strains should be added to the next years vaccination. Its a guessing game due to the high mutation rates of the influenza virus and the nearly 200 viruses that cause flu symptoms. Even if scientists knew what strains were circulating in the population at the very beginning of flu season, vaccination manufacturers wouldn’t be able to move quickly enough to make the “perfect match” vaccine. Remember, flu season only lasts a few months and peaks mid winter (Jan-Feb). What usually goes around in fall and in the spring is most likely rhino-virus, which causes common cold.
The Cochrane Collaboration summary below is put out from an international, non-profit, independent organization. Their goal is to provide up-to-date, accurate information about the effects of healthcare interventions. They look at all published research and come up with a summarized conclusion. If you want to know more about their methodology click [here]. Here is what was concluded on flu vaccines for healthy adults, published July 7, 2010
“Authors of this review assessed all trials that compared vaccinated people with unvaccinated people. The combined results of these trials showed that under ideal conditions (vaccine completely matching circulating viral configuration) 33 healthy adults need to be vaccinated to avoid one set of influenza symptoms. In average conditions (partially matching vaccine) 100 people need to be vaccinated to avoid one set of influenza symptoms. Vaccine use did not affect the number of people hospitalized or working days lost. Fifteen of the 36 trials were funded by vaccine companies and four had no funding declaration. Our results may be an optimistic estimate because company-sponsored influenza vaccines trials tend to produce results favorable to their products and some of the evidence comes from trials carried out in ideal viral circulation and matching conditions and because the harms evidence base is limited.”
So according to this report, even under ideal vaccination circumstances, if everyone got a flu shot, this only would save 3% of the population from having influenza symptoms. If flu vaccines were a casino game, you probably wouldn’t touch it!
My Conclusion: For the average healthy adult with average exposure It seems rational to forgo the flu shot, and focus on strengthening general immunity in other ways. Of course there are individuals that will have a much higher exposure rate, such as health-care workers, in which case it could be pertinent to get a flu shot depending on the circumstances.
Just a note about Vaccine Controversy: You may know of the huge controversy over mercury-based preservatives (Thimerisol) in vaccines. Many people feel this is a major danger to vaccine administration. These are only found in multi-dose vials, and not in single dose vials or the live virus nasal inoculation. If this is a concern you can ask for thimerisol free vaccines.
Bottom line: It seems that flu shots may not be what they are marketed to be. Any research that is funded by the vested beneficiary is a conflict of interest and should be a red flag for “collaborated” statistical computing. While it may be suitable in high exposure environments, for the average person, it may not be worth the risk until more objective studies are done. Just to be clear…I’m not concluding that vaccination is useless, just that vaccination is much more effective for virus strains with low mutation rates meaning they are pretty much the same creature year after year. This is how smallpox was able to be eradicated. Truly a gift from science! The smallpox virus has a much “cleaner” replication mechanism so it doesn’t make mistakes in its genome sequencing.
Next time I’ll look at my favorite immune boosters in gearing up for the flu season! Don’t worry there is still time!
Click [here] to try your hand at being a “disease scientist” . It’s fun and a good interactive illustration of the process of creating flu vaccines.