Can I get the flu from the flu vaccine?

No, you cannot get the flu from the flu vaccine (flu shot). This is a common myth. The flu vaccine is generally made of inactivated flu viruses. They are not infectious. Common side effects of a flu shot are soreness or redness at the injection site. Less often, some people who get a flu shot develop a low-grade fever, mild headache or muscle aches. These symptoms are due to the immune response your body is creating to fight the flu. These symptoms are also temporary and do not last as long as typical flu symptoms.

It doesn’t mean you have the flu. The flu is a serious illness–and the flu virus changes every year. So, it's important to get your flu shot every year, too.

The flu vaccine itself cannot cause the flu, but you could be exposed to the flu within two weeks after vaccination—before you have time to develop antibodies or immune resistance. Then, when you get sick, you might think the vaccine caused it.

You cannot get the flu from the flu vaccine. There are several reasons why one may feel feverish, have body aches or other symptoms similar to the flu after getting the flu shot. It takes two weeks or so for your body to be protected against the flu shot, so if you were exposed prior to the flu shot or within the first two weeks, you may get sick. Your body's immune system is working harder than usual after getting the flu shot, which can rarely cause low-grade fevers and chills for one to two days following the shot. There are also many other viruses (such as rhinovirus) that may act similar to the flu virus, and sometimes there are still strains of the flu virus that are not covered in the shot. We vaccinate against the flu because of the serious complications that can arise from influenza in particular. We recommend the flu shot in everyone over the age of six months when it is medically safe.

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Important: This content reflects information from various individuals and organizations and may offer alternative or opposing points of view. It should not be used for medical advice, diagnosis or treatment. As always, you should consult with your healthcare provider about your specific health needs.