How long does it take for the influenza vaccine to work?
The vaccine stimulates production of antibodies that provide protection against the influenza viruses in the vaccine. Influenza vaccine causes your body to generate protective immunity in about two weeks. The ability of the influenza vaccine to protect a person depends on the health status (immune system especially) and age of the individual, and the “match” or similarity between the virus strains in the vaccine and the circulating influenza strains. Studies have proven that both the influenza shot and the nasal-spray influenza vaccine are effective in preventing the influenza virus.
