The nasal version of a flu vaccine was discontinued more than a year ago, after it was found to be ineffective. Health officials worried that flu vaccination rates in children would drop—with only injectable flu vaccines available, it was thought people would avoid getting jabbed with a needle. But the numbers show there has been no drop, at least in one state.
The good news is that this worry was unfounded, based on data from Oregon. Health-care providers in Oregon immunized roughly the same number of people against flu in the 2016-2017 flu season as they had in previous flu seasons.
The Advisory Committee on Immunization Practices (ACIP) announced in 2016 that the nasal vaccine, FluMist, from AstraZeneca, was ineffective and advised against its use. It was found to be only about 3% effective against flu, compared to the 40% to 60% effectiveness of injected flu vaccine in most years. The nasal vaccine was made with a live attenuated influenza virus, while both trivalent and quadrivalent injected flu vaccines are made with dead virus.
For the study, a group led by Steve Robison of the Oregon Health Authority and colleagues looked at data from the Oregon statewide immunization registry called the ALERT Immunization Information System. They compared flu vaccination rates among children from the 2012-2013 through the 2016-2017 flu seasons.
They looked closely at data from the last two flu seasons. "We found that overall, there was no difference in childhood influenza immunization rates between the 2015-2016 season, when FluMist was widely used, and the 2016-2017 season, when FluMist was not used," Robison said.
Children who had previously received nasal vaccine were only slightly less likely to return for a flu shot in 2016-2017, they found.
Children ages 3 to 10 who had been given FluMist were 3% less likely to return than those given an injection, while adolescents 11 to 17 who had been given FluMist were 8% less likely to return, the study found. Children who previously received an injected flu vaccine were slightly more likely to return for vaccination during the 2016-2017 flu season.
The report was published online Oct. 6 in the journal Pediatrics.