Can the flu shot infect me with a virus?

Peter M. Lefevre, MD
Internal Medicine
The flu shot cannot infect you with a virus because the injectable form is an inactivated or “killed” virus to avoid causing the infection. In some cases, it can produce a minor immune response in the first 24-to-48 hours, including low-grade fever and muscle pain, as the immune system develops antibodies against the flu – but that is nothing compared to the potentially severe and life-threatening symptoms of the flu itself.
This content originally appeared online at UCLA Health.
Diana K. Blythe, MD

The flu shot cannot infect you with a virus because it does not contain a live virus. What the flu shot does is train your body to fight off the influenza virus if you are exposed.

After a flu shot, you may feel a mild elevation in your temperature or some soreness in the arm at the injection site. Moving your arm will help with the soreness.


The flu shot cannot infect you with a virus. The shot contains viruses that have been killed and therefore have no ability to infect your body. Flu vaccine manufacturers also test their products for safety.

Continue Learning about Vaccine



Vaccines work to protect your body against germs. Because of vaccines, many of the diseases that can cause severe sickness, handicaps and death have been eradicated. Learn more from our experts about vaccines.

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.