I'm Healthy. Do I Need a Flu Shot?

You might not be familiar with the Cochrane Database for Systematic Reviews. It's a medical research organization dedicated to parsing all the other medical research. The writers who submit to Cochrane sift through dozens of related studies in order to distill all that knowledge into useful nuggets. There might be fifty studies all looking at one issue: the Cochrane folks blend all those studies into one big study, one meta-analysis.

This year, Cochrane published a systematic review entitled "Vaccines for preventing influenza in healthy adults". They included 15 clinical trials "funded by industry", which means that the vaccine manufacturers paid for these trials in order to prove the effectiveness of their own vaccines. It's like getting a stamp of approval before they submit their product to the Food and Drug Administration.

Before I analyze this fascinating study, allow me to state: I believe that the decision to use or not use vaccines are a personal right and responsibility. I believe that there is a place for vaccines, and that vaccines have played a role in the eradication and suppression of many terrible diseases. I also believe that vaccines, like antibiotics, tend to be overutilized. I do not advise any patient for or against a particular vaccine, although I do try to collect facts.

Bear in mind, too, that this article does not touch on the controversial issue of vaccinating children. This study specifically looked to healthy adults.

So, suppose that you're a healthy person (I hope you are). You live in Peoria, in central Illinois, surrounded by millions of other healthy, vaccinated individuals. You see advertisements everywhere encouraging everyone to "Go get your flu shot!" You are told that if you don't get vaccinated, you put your Grandmother and your Children at risk. What to do?

Dr. Charles Vega of Medscape wrote a very lengthy and excellent summary of the article, and so I will simply quote him here: "Overall, the current review finds that the evidence for universal vaccination of all healthy adults is underwhelming. Even when the vaccine was well-matched to the circulating virus, vaccination against influenza was far from fully protective against infection. Moreover, the flu vaccine had a minimal impact on the number of days of work missed, and it did not prevent complications of influenza.

"Unfortunately, a recent review of influenza vaccination among adults at age 65 or older also suggested that the vaccine was of questionable efficacy. While vaccination appeared to reduce the symptoms of influenza, the heterogeneity and poor quality of the collected research prevented any strong conclusion regarding the effectiveness of the vaccine in preventing complications of influenza in this high-risk population.

"Analyses from the Cochrane Database of Systematic Reviews regarding the use of the influenza vaccine clearly state a need for better evidence of vaccine efficacy, and they are also quite pointed in their critique of public health efforts to increase the usage of the vaccine. The current article states, 'The CDC [Center of Disease Control] authors clearly do not weight interpretation by quality of the evidence, but quote anything that supports their theory.'"

Not only is universal flu vaccination a "theory", but it is weakly supported by facts. The reason is simple, and fairly well known by now: in order to create enough flu vaccine to inject every person, the manufacturers need plenty of time. It's not easy to produce billions of vials. That means that they need to start producing flu vaccine before the current flu strain is established, so they have to forecast the flu strain. In this respect, the flu vaccine is unlike any other vaccine. Whether the forecast is accurate or not, the product still needs to be sold or underwritten in order to reimburse the manufacturer. Beyond the economics, there are apparently a number of biochemical reasons why the forecasted strains react poorly with your immune system.

Feel free to follow the above links to read the article itself, or Dr. Vega's comprehensive summary.