By Mary Elizabeth Dallas
FRIDAY, Sept. 1, 2017 (HealthDay News) -- Seasonal flu immunization rates among children appear to have dropped slightly after the U.S. Centers for Disease Control and Prevention recommended against the nasal spray version of the vaccine, researchers report.
But it's not just shot-avoidance that prevents people from getting the recommended vaccine. Researchers found that up to half of all Americans are fickle about the flu shot and change their minds about getting vaccinated from one year to the next.
"It seems that people may not be either vehemently pro flu vaccine or anti flu vaccine," said the study's co-author, Ben Fogel. "Rather, if it's convenient, they'll get the vaccine, and if it's not convenient, they won't go out of their way to get it," said Fogel, an assistant professor of pediatrics at Penn State College of Medicine.
Convenience was a main selling point for the nasal spray form of the flu vaccine, the researchers said. Parents often opted to give their child the nasal spray, viewing it as easier and less painful than the shot. Early on, studies suggested the nasal spray was also more effective for young children than the injection, the study authors noted.
By 2016, however, additional studies found the nose spray was actually less effective than the shot in preventing the H1N1 strain of influenza. These findings prompted the CDC to reverse its recommendation and advise against the nasal spray for the 2016-2017 flu season.
"We wanted to understand what happened to vaccination rates with this new recommendation," Fogel said in a university news release. "Would this recommendation against nasal spray vaccine shake people's confidence in the influenza vaccine in general or make them less likely to get it because they have to get a shot?"
To answer these questions, the researchers analyzed total vaccination rates among more than 9,500 children aged 2 to 17 years during three consecutive flu seasons, starting in 2014.
Fewer children were immunized once the nasal spray was ruled out, the findings showed.
Total flu vaccination rates among kids in the 2016-2017 flu season dropped 1.6 percent from the year before. On a national scale, that would mean some 1.2 million more children would go unvaccinated, the study authors explained.
"This could potentially lead to 4,385 additional influenza-related outpatient visits and 30 additional influenza-related hospitalizations among the 74 million children under the age of 18 in the U.S.," Fogel and colleagues wrote.
The study also found that vaccination rates fell more among the kids who had received the nasal spray in the 2015-2016 flu season. Also, black and Hispanic teens with public insurance who were vaccinated in the 2015-2016 flu season were also less likely to get vaccinated the next year.
However, things could have been worse. "We saw a drop off but I would not call it huge, which is reassuring," Fogel said.
The study was published online recently in the journal Vaccine.