Earlier studies have suggested that having repeated annual influenza vaccination can prevent natural immunity to the virus, and potentially increase the susceptibility to influenza illness in the event of a pandemic, or when the vaccine does not ‘match’ the virus circulating in the community. But now, researchers at the Influenza Center in Bergen have published a study, which concludes that annual influenza vaccination does not increase susceptibility to influenza infection in years of vaccine mismatch.

https://www.sciencedaily.com/releases/2017/11/171113111055.htm