How long does it take for immunity to develop post-vaccination?
According to the CDC, once you get vaccinated, your body makes protective antibodies in about two weeks. However, children younger than 9 years old who are being vaccinated for the first time need a second dose 4 or more weeks later in order to be protected. CDC has stated that the ability of the seasonal flu vaccine to protect a person depends on at least two things: 1) the age and health of the person getting the vaccine, and 2) the similarity or “match” between the virus strains in the vaccine and those being spread in the community. Keep in mind that vaccine effectiveness is not 100%, and some people can still get the flu. For instance, some older people and people with certain chronic illnesses might develop less immunity than healthy young adults after vaccination. However, even for these high-risk individuals, the seasonal flu vaccine still can provide protection against getting severe complications from seasonal flu.
