There is more evidence than ever to get your flu shot – and get it every year – is a…
There is more evidence than ever to get your flu shot – and get it every year – is a good idea. Some studies had previously suggested that repeated vaccinations year after year could reduce the effectiveness of the shot, although most findings were inconsistent and inadequate. Now, a newer and larger study has not found any evidence of such effect. In fact, researchers say that vaccination every year seems to increase immunity in some cases.
The New Study published last week in JAMA included more than 3,000 children between the ages of 2-1
7, all visiting the acute respiratory disease doctor between 2013 and 2016. All visits were during the flu season, but only 23% of patients tested positive for the flu.
When they looked at the patients immunization register, Researchers found that children who had been vaccinated during the current flu season, as in the past, were less likely to be diagnosed with flu than those vaccinated during the current season.
RELATED: Why should you get flu offense every year
The effects vary with influenza type (influenza A or B), depending on the vaccine type (nasal spray against the flu) and the year. But overall, there was no scenario where vaccination for two consecutive years was associated with lower efficacy than vaccination only during the current season.
“In other words, there were no signs of reduced vaccine efficacy in frequent vaccines, although the study included seasons where such effects had been reported elsewhere,” wrote Sarah Cobey, PhD, Professor of Ecology and Evolution at the University of Chicago in a related comment. The study is “important advances” to better understand influenza vaccine efficiency, wrote Cobey as well.
In some cases, few influenza vaccines seemed to increase the protection each year. For example, children who had received FluMist nasal spray during the current season were less prone to having the H3N2 (the most dangerous type to circulate last year) if they had also been vaccinated last year. 19659002] RELATED: 25 Survival Cold And Flu Season
And for the flu B of two common influenza types that circulate seasonal in the United States – a previous year’s vaccination appeared to provide some remaining immunity, even for children who had not been vaccinated again during the current season.
The researchers found similar results for further analyzes that also included vaccinations for two and three previous seasons.
Since the study was done in children, it is not clear if the same pattern would apply to adults. (A study published earlier this year However, the Canadian Medical Association Journal found that repeated vaccination is protective for people over the age of 65.) And because each flu season is different and each year’s vaccine has different levels of effectiveness studyers say that there is still a lot to learn.
RELATED: The 10 largest myths about influenza
“In order to better understand the effect of repeated vaccination on the effectiveness of the vaccine, further studies are required each season, for each vaccine type, in different populations,” said Huong McLean , doctor, researcher at Marshfield Clinic Health System and first author of the study Health .
.] But for now she says the results are calm, especially for parents wondering if their children should be vaccinated every year. “Getting flu vaccination every year is still the best way to protect against the flu,” says McLean.