Remember the summer of 2009? I do! The pediatrician’s office in summer is usually lazy days of school physicals and summer-fun-related injuries. But that summer the office was packed with high fevers, cough and severe body aches: summer camps shut down, entire families suffered together. That was the H1N1 epidemic, which caused a public health emergency in the US and globally.
In 2003, nasal flu vaccine was introduced with three strains, the same as those included in the injectable vaccine. Early studies showed good efficacy, in fact, even better efficacy for the mist than the injection. (Joy!) When the H1N1 strain was incorporated in the nasal vaccine in 2013, it appears that the efficacy plummeted. Vaccine effectiveness for H1N1 with mist was -21%! Kids who got mist were almost 4 times more likely to get influenza than kids who got the injectable vaccine. There are multiple hypotheses for why this happened: perhaps there was a problem with the H1N1 strain, or perhaps the 4th strain caused interference, or perhaps as more kids are in the “previously vaccinated” category, the mist does not generate an adequate immune response.
No matter the reason, here we are: no FluMist. ACIP and AAP still recommend flu vaccination for all kids 6 months and over. Alternative vaccine forms are in the works, some already approved for adults, like a jet injector (very Star Trek), but for now kids will get a flu injection.