Every year the flu season comes around and every year you have to make a decision of whether or not you are going to get vaccinated. If you have children, you also need to decide if you will get them vaccinated or not. Trust me when I say that can be a traumatic experience! I’ve also learned that flu shots can be a very sensitive issue for lots of people. The Centers for Disease Control and Prevention (CDC) estimate that roughly 200,000 people are hospitalized and 36,000 people die from the flu annually. The CDC offers a great deal of information about the flu as well as information about the types of flu vaccines offered. There basically are two types of flu vaccines available. The first is the flu shot, sometimes referred to as trivalent inactivated influenza vaccine. The flu shot is considered “inactivated” because it contains killed flu viruses.
The second type of vaccine is the flu mist or nasal spray. You will sometimes see this type of vaccine referred to as live attenuated influenza vaccine. The spray or mist is considered “live” because it contains live, but weakened flu viruses. Both vaccines have been approved by the Food and Drug Administration and neither of the vaccines will result in you getting the flu. The live attenuated vaccine is newer (only commercially available since about 2003) than the inactivated vaccine, however, some people can be hesitant to get the flu spray or mist because they are worried about the “live but weakened” nature of the vaccine. A very nice article by Tosh et al., (2008) describes how the live attenuated vaccine is both a safe and effective vaccine. So, why do you sometimes feel like you get the flu after you get a flu shot? The body can sometimes experience an immune response to a flu shot which can result in flu like symptoms. These symptoms can include muscle aches, headache, fever, cough, and a sore throat.
Tosh P, Boyce T, Poland G: Flu myths: dispelling the myths associated with live attenuated influenza vaccine. Mayo Clinic Proceedings (2008), Vol 1, pps. 77-84.