As if the US community isn’t already paranoid enough about the H1N1 swine flu virus and its vaccine, this week, Sanofi Pasteur, the vaccines division of the sanofi-aventis Group in France, recalled 800,000 prefilled vaccines.
The recall, according to the Centers for Disease Control and Prevention (CDC), didn’t have to do with a safety issue (whew!) but rather, a potency problem. In post-shipping stability tests, a few lots of the vaccine did not reach the pre-specified potency limit. Specifically, three lots that had been distributed “had an antigen content that, while properly filled at the time of manufacturing, was later measured to be below pre-specified limits,” according to the CDC fact sheet. It is common to test for stability after a vaccine’s distribution to see how well the drug maintains its potency. Unfortunately, in this case, these particular lots did not measure up.
To make matters worse, the particular lots recalled were meant for children between the ages of 6 months and 35 months, one of the populations at particular risk for getting the swine flu. For many parents, the decision of whether or not to give their child a swine-flu vaccination has been a difficult one. The recall only adds to these parents’ mental debate.
Fortunately, CDC notes on its website that patients who already received the recalled vaccine should be fine—there is no medical danger involved and no further action is necessary. Although I have to wonder how well a vaccine whose potency is less than optimal will work if a vaccinated child is exposed to the virus.