If you received a nasal spray flu vaccine from 2013 to 2016 and came down with the virus anyway, you're not alone. In fact, the live attenuated influenza vaccine (LAIV) was found to have no protective benefit in a study of children ages 2 to 17 during the 2015-2016 season. That's why the Centers for Disease Control announced earlier this week that nasal spray vaccines should not be used for the 2016-2017 flu season. Bad news for anyone with a severe fear of needles.
No vaccine is perfect. The CDC reported that the injected vaccine for last season was 63% effective for patients in the same age group, but that's much better than nothing.
"The reason for the recent poor performance of LAIV is not known," the CDC said.
According to Scientific American, experts did not expect such poor results from the nasal spray, sold as FluMist, because earlier studies showed that it was either as effective as, or even more effective than injected vaccines. A number of factors affect how well the spray, which contains a small amount of live virus strains, can protect patients. The strain of H1N1 flu virus included in the spray may degrade if it's exposed to high temperatures during shipping, for instance. Injected vaccines use inactivated viruses and virus particles.
Before this announcement, FluMist was supposed to supply about 8% of the vaccines for the 2016-17 season, so this decision means that other vaccine manufacturers need to up the difference before the summer is over. Don't use this as an excuse not to get a shot altogether this winter. The CDC maintains its recommendation that everyone over 6 months old receive a flu vaccine.