IFITM3 and influenza: This result strongly suggests that IFITM3 genotype may have little impact on the efficacy of seasonal Vaccination in young healthy adults, however its impact on live attenuated influenza Vaccine and on seasonal influenza virus vaccination of elderlies still merits a further investigation, as the potential restriction of live attenuated virus by IFITM3 may affect the intake of the Vaccine and therefore the immune responses.