Flu vaccine immunity — meaning immune system protection — doesn't last long. After about 6 months, your immunity starts to fade. This falling level of protection (from a lessening amount of antibodies), combined with ever-mutating flu viruses, means it's important to be vaccinated for the flu every year.Dec 14, 2021
How long after flu shot are you protected?
Does flu vaccine work right away? No. It takes about two weeks after vaccination for antibodies to develop in the body and provide protection against influenza virus infection. That's why it's best to get vaccinated before influenza viruses start to spread in your community.Nov 18, 2021
How long does the flu vaccine protect you?
Protection lasts around 6 to 8 months, starting two weeks after you receive the vaccine. Once the season ends, the flu shot does not protect you any longer: you will need a new vaccination for the following year's season. In fact, you should get the shot with the current season's vaccines the FDA approves yearly.Oct 28, 2021