By Drs. Kay Judge and Maxine Barish-Wreden
True or false: The flu shot can give you the flu. False, says the Centers for Disease Control and Prevention. The flu vaccine contains killed viruses, which means the flu shot cannot cause infection. The Centers for Disease Control and Prevention found that “The only differences in symptoms was increased soreness in the arm and redness at the injection site among people who got the flu shot. There were no differences in terms of body aches, fever, cough, runny nose or sore throat.”
For some people who notice symptoms immediately after the flu shot, it can be from the immune system making antibodies to the killed viruses in the vaccine that help fight off the flu.
True or false: The nasal flu vaccine can give you the flu. False. Unlike the flu shot, which contains killed viruses, the nasal spray vaccine does contain live viruses. However, the viruses contained in the nasal-spray flu vaccine are attenuated (weakened), which means they cannot cause flu illness. These weakened viruses are designed to cause mild infection at the cooler temperatures found within the nose, but they cannot infect the lungs or other warmer areas of the body.