Is “An ounce of prevention worth a pound of cure”? In regard to the flu shot, there is always much debate. Does the flu shot actually prevent the flu? Does a person risk getting the flu from the flu shot? How do scientists know what to put in the flu shot? Why doesn’t it work every time and for every person?
The Center for Disease Control (CDC) recommends that everyone age six months and older receive the flu shot. But many people don’t follow this advice. Hopefully, the answers to the questions posed above will help you make an informed decision.
The flu shot is made-up of three types of killed viruses. Because these viruses are dead, they cannot infect you and therefore, the flu shot cannot cause the flu. However, these dead viruses still have the ability to stimulate your immune system. It is for this reason that you can gain immunity from the flu. Because, viruses frequently change structure (mutate) and because only three viruses are included in the vaccine, the flu shot may fail to protect you or only blunt the flu’s ill effects.
Because the flu shot is given during flu season, some people receiving the shot are already infected with the flu and are unknowingly about to become sick. When this illness occurs shortly after receiving the vaccine, the shot is blamed.
So how do scientists determine which strains are most likely to infect us? Currently, 130 influenza centers in 101 countries conduct year-round surveillance. These laboratories send influenza viruses to five World Health Organization Centers. The northern hemisphere gets to know what's likely to hit them in February for the following winter, and the southern hemisphere in September for the same. The more of us that get the vaccine, the less likely it is to spread to those we love.