Will Your Flu Shot Work This Year?
A Centers for Disease Control and Prevention (CDC) advisory committee of medical and public health experts recommends that everyone over age 6 months get an annual flu shot.
However, the vaccine doesn’t prevent flu in everyone who gets it. In fact, according to the CDC, last year’s influenza vaccines reduced medical visits for flu by just 42 percent overall. Nonetheless, widespread vaccination is key to preventing large flu outbreaks.
Researchers have discovered one important reason why the flu shot doesn’t always work: The way flu vaccines are manufactured causes influenza viruses to mutate even more than, and faster than, they are already prone to do. Most flu vaccines are grown in chicken eggs, and they need to mutate in order to grow. The process is slow, taking weeks or months, and tricky – there are many opportunities for something to go wrong.
This problem has worsened in recent years, researchers say, and is one reason more modern methods of making flu vaccines must be developed. The two alternatives currently approved for testing in the United States are Flucelvax, which is grown in canine kidney cells, and FluBlok, which uses an insect virus, called baculovirus, which is grown in caterpillar cells. The hope is that these vaccines will someday provide better protection from the flu.