CDC studies suggest that the effectiveness rate of the flu vaccine (FV) this season may be lower than last season.[1] This concerns protection against outpatient visits and hospitalizations.[1] The lower efficacy is partly due to a mismatch between the virus in the vaccine and the circulating strains of the virus.[1][3] The effectiveness of influenza vaccines varies each season according to the match of the vaccine composition to the circulating strains.[1] With antigenic drift, the effectiveness against hospitalizations can reach around 35% in risk groups, in better years 50% or more.[1] Even with lower compliance, the vaccine provides partial protection, alleviates the course of the disease and reduces the risk of complications.[1][3] In England, the estimated effectiveness against hospitalizations remains at 70-75% in children and 30-40% in adults.[3] Even with drift, vaccines protect against a severe course, hospitalizations and death.[3]