Two are better than one for flu vaccination in children

Two doses of the influenza vaccine were more effective than one dose, confirming the US influenza vaccine policy, the researchers report.

Among 7,533 children aged 6 months to 8 years, a primer dose followed by a booster dose was more effective than the single dose vaccine (58% vs. 46%) and the data adjusted influenza Reported low odds (adjusted odds ratio) of 0.61, 95% CI 0.40 to 0.94), Atlanta CDC Jessie R. Chung, MPH, and colleagues.

In a subset of unvaccinated children under 2 years of age, two doses of vaccine were much more effective than one (53% vs. 23%) and less likely to have influenza (aOR 0.57, 95% CI). 0.35) -0.93), written by researchers JAMA Pediatrics.

Overall, only 39% of children in the cohort were considered fully vaccinated, with 1 or 0 doses in the previous flu season and 2 doses in the current season, or more than 2 in the previous season And is currently defined as receiving one or more doses. Season.

“Reducing the burden of influenza disease, especially on infants vulnerable to complications and mortality due to influenza infection, by facilitating efforts to improve the coverage of influenza vaccines, especially by giving twice the first vaccination season. You can do it, ”wrote Chung and co-authors.

CDC The Advisory Committee on Vaccination Practices Children aged 6 months to 8 years who have not been vaccinated or have received a single dose in the previous season will receive two doses at least 4 weeks apart.

Notably, the only vaccine licensed was a half-dose product until the 2018-2019 flu season, so we didn’t assess the vaccine’s efficacy in children who were initially vaccinated with a full-dose vaccine. The authors reported.

These findings have consistently shown that fully vaccinated children are “more likely to achieve protective levels of antibody titers and less likely to be hospitalized for influenza-like illness”. “Reinforces the study of.” Melissa Stockwell, MD, MPH, and Columbia University of New York University, both at Clare Abraham, Maryland, The accompanying editorial.

They also found that less than half of the children were completely accepted in this study, so what barriers, such as parental hesitation, inconvenience, and lack of counseling, might lie in the recommended non-medicated family. Vaccination added that the study also emphasized the need to understand.

“This study may be useful to tell parents that a single dose does not provide significant protection against influenza, especially for unvaccinated children,” says Stockwell and Abraham. I am emphasizing.

In this study, children with acute respiratory illness and cough were treated on an outpatient basis. Influenza vaccine efficacy (VE) network. This includes 5 sites nationwide during the 2014-2015 and 2017-2018 flu season. The disease was confirmed through nasal and oropharyngeal swab preparations tested via the reverse transcriptase polymerase chain reaction.

It was excluded if a child was vaccinated within two weeks of onset, had already been vaccinated twice in the enrollment season, or had live attenuated flu vaccine during that season. Data were adjusted for study location, influenza season, age, calendar time, comorbidities such as asthma.

Of the 7,533 children included, 46% were female, 62% were white, and 65% were under 5. Although one in five children was unvaccinated, two-thirds (68%) were vaccinated before this season and 12% were vaccinated for the first time in the current season.

Children who received two doses within the first vaccination season (60%) were younger than those who received a single dose (median 8 vs. 11 months) at the time of the first vaccination and were non-Hispanic white (68%). %) And privately insured (40%), the authors reported.

Residual confounding can play a role in findings, especially because families are financially compensated and children who receive recommended medications may have different care-seeking behaviors than those who did not. The authors said. Additional restrictions included relatively small sample sizes across the four influenza seasons and lack of stratification by initial vaccine type, the researchers added. Finally, they said, the study focused primarily on the circulation of influenza A (H3N2), with some influenza B and a few influenza A (H1N1) pdm09.