Key Takeaway:
- Harvard researchers found that Child Flu Vaccines prevent 9 to 14 flu cases for every 100 vaccinated children ages 2 to 5.
- CDC data shows about 85% of child flu deaths this year occurred in children who were not fully vaccinated.
- Researchers say the study provides strong evidence that annual flu vaccines reduce illness and severe outcomes in children.
Child Flu Vaccines prevent hundreds of thousands to nearly 1 million flu infections among U.S. children each year, according to new research from Harvard Medical School. The study found that Child Flu Vaccines significantly reduce illness rates among children ages 2 to 5 and help prevent severe outcomes, including death.
The study’s findings come as public health officials continue to confront vaccine hesitancy and misinformation that have contributed to declining vaccination rates and outbreaks of preventable diseases.
Researchers found that for every 100 children ages 2 to 5 who receive a flu vaccine by injection or nasal spray, between nine and 14 flu cases are prevented. The analysis was based on national insurance claims data collected over five flu seasons between 2016 and 2023, excluding the COVID-19 pandemic years from 2020 through 2022.
“In the United States, that’s hundreds of thousands, if not a million cases of flu that we can avoid each year,” said Anupam Jena, Joseph P. Newhouse Professor of Health Care Policy at Harvard Medical School’s Blavatnik Institute. “That’s a huge effect size.”
Researchers Show Vaccines Cut Flu Infections in Young Children
The study examined vaccination and flu diagnosis rates among children born at different times of the year. Researchers used birth month as a natural comparison because young children often receive annual checkups around their birthdays.
Children with fall birthdays were more likely to receive Child Flu Vaccines because they become available during the fall. Those with summer birthdays often needed an extra doctor’s visit to be vaccinated, resulting in lower vaccination rates.
Researchers found vaccination rates among children with fall birthdays were 8.6% to 12.5% higher than among children with summer birthdays.
“Across these five seasons, we see that for every hundred kids who are randomly vaccinated because of when their birthday falls, somewhere between nine and 14 of them avoid a case of the flu that they otherwise would have caught,” Jena said.
CDC Data Link Most Child Flu Deaths to Low Vaccination Rates
Health officials say vaccination remains one of the strongest protections against severe illness and death from influenza.
According to the Centers for Disease Control and Prevention, flu vaccination prevented 10 million illnesses and 12,000 deaths across all age groups during the 2024-25 flu season.
The agency also reported that flu vaccination reduced the risk of flu-related death by more than 75% among children with underlying medical conditions and by more than 85% among otherwise healthy children.
Despite those benefits, vaccination rates have declined in recent years. Researchers said nearly 90% of pediatric flu deaths reported in September involved children who were not fully vaccinated. This year, approximately 85% of child flu deaths occurred among children who were not fully vaccinated.
Study Counters Claims Questioning Flu Vaccine Effectiveness
The findings arrive amid debate over vaccine policy. Earlier this year, federal officials removed recommendations for annual flu vaccinations, a move later blocked by a U.S. District Court.
“The federal government cited an absence of evidence that they wanted to see, and so we have provided that,” said Christopher Worsham, an assistant professor of medicine at Massachusetts General Hospital. “We have randomized data, and it shows that Child Flu Vaccines are effective for these young children.”
Researchers noted that while vaccine effectiveness varies from season to season, vaccination consistently lowers the risk of infection and serious complications, particularly among children.
Public health experts say the new findings reinforce longstanding recommendations that eligible children receive annual flu vaccinations to reduce illness, hospitalization, and death.
Visit Healthcare 360 Magazine For The Most Recent Information.
