Fact Check: RFK Jr. Misrepresents What the Science Says About Flu Vaccines and Children
“The Cochrane Collaboration, which is kind of one of the ultimate arbiters of vaccine safety and clinical data, has done an extensive meta review of the flu vaccine. They found that there is no evidence that the flu vaccine prevents serious disease or that it prevents hospitalizations or death in children. There’s no scientific evidence. And what we tried to do is to follow the science.” (jump to 5:56)
— HHS Secretary Robert F. Kennedy Jr.
The Cochrane Collaboration is a leading global organization that evaluates medical research and rates the strength of the evidence. But when HHS Secretary Robert F. Kennedy Jr. uses Cochrane’s findings to say there’s “no evidence” that flu shots keep kids out of the hospital, he’s not using gold-standard science. He’s misreading what those studies can actually show.
Cochrane’s reviews don’t say flu shots fail. They say the studies they include, mostly small randomized trials, don’t have enough data to measure rarer, serious outcomes. That’s very different from proving vaccines don’t work.
Cochrane Reviews are among the most trusted sources in medicine. They focus on randomized controlled trials — the kind of research that best limits bias — but that focus also creates limits. Flu vaccine studies in children are often small and last only one season. They track mild flu cases, not hospitalizations or deaths, which are far rarer. So when Cochrane says “no data on hospitalizations were reported,” it means the studies didn’t measure that outcome, not that the vaccine doesn’t prevent it.
What the Cochrane Reviews Actually Say
Let’s look at the Cochrane papers themselves.
In “Vaccines for preventing influenza in healthy children,” the reviewers wrote that “data on the most serious consequences of influenza complications leading to hospitalisation were not available.”
They found that both live and inactivated (killed-virus) flu vaccines helped keep kids from getting the flu, especially those older than two. The evidence was strong for preventing regular flu infections, but the studies were too small to tell whether the shots also kept kids out of the hospital.
The same pattern appears in Cochrane’s other reviews of influenza vaccines:
Among healthy adults, the authors concluded vaccination “may have little or no appreciable effect on hospitalisations (low-certainty evidence).” That doesn’t mean there’s no benefit, just that the studies weren’t large enough to tell.
Among adults 65 and older, the reviewers wrote that “no data on hospitalisations were reported” and “the study providing data for mortality and pneumonia was underpowered to detect differences.”
Across all age groups, the Cochrane reviewers stressed that the trials they analyzed were limited, old, and too small to capture rarer outcomes like hospitalization or death.
What Other Evidence Shows
Outside Cochrane’s narrow lens, there’s a mountain of real-world evidence showing that flu vaccines protect kids from serious illness. Large studies that track millions of people across multiple flu seasons consistently find that vaccination sharply reduces the risk of hospitalization from influenza:
“Updated Evidence for COVID-19, RSV, and Influenza Vaccines for 2025-2026” reported a 40-60% reduction in flu-related hospitalizations among vaccinated patients.
“Interim Estimates of 2024-2025 Seasonal Influenza Vaccine Effectiveness — Four Vaccine Effectiveness Networks, United States, October 2024-February 2025” found that among children and adolescents under 18 years, the 2024-2025 influenza vaccine reduced the risk of influenza-associated hospitalization by 63% to 78% and outpatient illness by 32% to 60%, providing strong protection against severe flu even during a season dominated by influenza A(H1N1)pdm09 and A(H3N2) viruses.
“Influenza Vaccine Effectiveness Against Hospitalizations and Emergency Department or Urgent Care Encounters for Children, Adolescents, and Adults During the 2023-2024 Season, United States” showed nearly identical results: vaccinated children were 58% less likely to be hospitalized and 71% less likely to need hospital care if under five.
“Vaccine Effectiveness Against Life-Threatening Influenza Illness in US Children” found that influenza vaccination reduced the risk of critical influenza illness in children by 63% overall and life-threatening influenza by 75%, even during a season when most circulating viruses were vaccine-mismatched.
Other studies point the same way:
“Real-world effectiveness of influenza vaccination in preventing influenza and influenza-like illness in children” found that the shot and nasal spray versions of the vaccine were 43-54% effective in preventing illness over two flu seasons.
“Vaccine Effectiveness Against Pediatric Influenza Hospitalizations and Emergency Visits” showed that in 2018-2019, vaccination reduced hospitalizations by 40% and ER visits by 50%, even against a drifted H3N2 strain.
“Estimated Vaccine Effectiveness for Pediatric Patients With Severe Influenza, 2015-2020” found a 50-56% reduction in emergency department visits and hospitalizations in children, with similar protection across all levels of illness severity, including critical hospitalizations requiring ICU care.
“Influenza Vaccine Effectiveness Against Pediatric Deaths: 2010-2014 showed vaccinated children were 65% less likely to die from influenza: clear protection against the most severe outcomes.
These are not “no evidence.” They are strong evidence. Cochrane’s reviews don’t include these large-scale studies because they only accept randomized controlled trials, the type of research in which people are randomly assigned to receive a vaccine or a placebo. That’s a useful way to limit bias, but it also means excluding the enormous real-world observational studies that can detect rare outcomes like hospitalizations or deaths.
The Cochrane review on healthy children even states that observational studies were retained only for historical purposes and not analyzed in the main results. So when Cochrane says there’s “no data on hospitalizations,” it doesn’t mean vaccines don’t prevent them. It means that the small trials included simply didn’t measure them.
Understanding Cochrane Reviews
Cochrane Reviews are known for being strict. They ask a very specific question like, “What do randomized trials show?” and ignore almost everything else. That’s their strength: they filter out bias. But it’s also their weakness: when trials are small, old, or underpowered, they can’t capture big-picture outcomes.
Their careful phrases — “no data reported,” “low-certainty evidence,” “underpowered to detect differences” — aren’t proof that vaccines fail. They are signs that the evidence Cochrane chose to include wasn’t large enough to show a clear effect.
Think of it like this: if you flip a coin twice and get heads both times, you can’t conclude coins never land tails. You just didn’t flip enough times.
Verdict
Robert F. Kennedy Jr.’s claim distorts what Cochrane actually found. The reviews do not say that flu vaccines fail to prevent hospitalizations or deaths in children. They say that the randomized trials included in those reviews did not adequately measure those outcomes. Modern, large-scale studies clearly show that flu vaccination lowers the risk of severe illness and hospitalization.
Rating: ❌ False
Cochrane did not find “no evidence” of benefit. It found not enough data to measure the effect. That’s a big difference.