How effective is the nasal-spray seasonal flu vaccine LAIV (FluMist®)?

In one large study among children aged 15-85 months, the seasonal nasal-spray flu vaccine LAIV (FluMist®) reduced the chance of influenza illness by 92% compared with placebo. In a study among adults, the participants were not specifically tested for influenza. However, the study found 19% fewer severe febrile respiratory tract illnesses, 24% fewer respiratory tract illnesses with fever, 23-27% fewer days of illness, 13-28% fewer lost work days, 15-41% fewer health care provider visits, and 43-47% less use of antibiotics compared with placebo. Continue reading →