The Flu Shot: Great in 2008 or Unclear Like Last Year

By Leane Scoz

Every February, a Food and Drug Administration (FDA) Advisory Committee convenes to decide on the three influenza virus strains that will make up the influenza vaccine for that year. Their decision is based on global surveillance for influenza viruses and the emergence and spread of new strains. If they get it right, millions of people who receive the influenza vaccine for that year will be protected from the virus and can go on with their daily lives without interruption. If they get it wrong, the millions of people who took the time out of their busy lives to get themselves and children vaccinated will be at the same risk as people who chose not to get vaccinated. Last year, the Committee got it wrong.

When the Committee selects strains that match the circulating viruses well, the influenza vaccine reduces laboratory-confirmed influenza by approximately 70% to 90%. According to the CDC, the 2007 influenza vaccine was only 44% effective in preventing the influenza virus. A bad selection for one of the strains is to blame.

The poor success rate of the influenza vaccine last year led the Committee to select three new strains for the influenza vaccine this year. Normally, only one or two strains change each year. In fact, a three strain change has never occurred in the past. What does this mean for the 2008 influenza season?

Most manufacturers of the influenza vaccine were not anticipating a three strain change since it has never occurred in the past. They were probably all ramping up their supply of strains selected last year in hopes that one or more would have been selected again for the vaccine this year. When the FDA selected the three different strains this year on February 21, 2008, influenza vaccine manufacturers probably panicked at first and then kicked into high gear to ensure they will be able to produce as many vaccines as last year and get them to market as soon as possible to have an edge on competitors.

If vaccine production does not go as planned this year, will the country be faced with a shortage similar to the 2004 influenza season? Possibly, but a shortage is not likely to occur since multiple manufacturers now exist for the influenza vaccine compared to only two when the shortage occurred in 2004.

The success rate of this year’s influenza vaccine will not be known until early next year, however, people should not be discouraged from getting vaccinated Every year, influenza infects up to 20 percent of the U.S. population, causes the hospitalization of over 200,000 people, and is responsible for more than 36,000 deaths. If you add up the people at highest risk, more than 200 million people should be vaccinated each year. Manufacturers produced over 130 million doses of influenza vaccine last year, and more than 20 million were not used and had to be discarded. People do not take the influenza virus serious enough, and if the success of the vaccine is compromised each year, the pattern of not getting vaccinated will unfortunately continue.