New evidence review finds flu, RSV and COVID-19 vaccines continue protecting infants and children from severe illness

An independent evidence review released this week by the Vaccine Integrity Project and the American Medical Association (AMA) reinforces that influenza, RSV, and COVID-19 immunizations continue to meaningfully protect infants and children against severe respiratory illness, hospitalization, and death, with no new pediatric safety concerns identified.¹ The review, which screened nearly 19,000 studies published since August 2025 across the 3 viruses, helped shape the 2026-27 respiratory virus immunization recommendations issued jointly by the American Academy of Pediatrics (AAP) and 3 other medical societies.¹

“Immunization continues to be one of our best tools for preventing severe illness from respiratory viruses,” said Michael T. Osterholm, PhD, MPH, executive director of the Vaccine Integrity Project. “This year’s review confirms that the newest evidence remains consistent with research showing these immunizations reduce the risk of hospitalization and death among the people most likely to experience serious disease.”¹

Influenza vaccine data in children and pregnant patients

The influenza review screened more than 5800 studies and identified 69 newly published studies, including 21 randomized controlled trials.¹ A case-cohort analysis of 8 seasons of national surveillance data found vaccine effectiveness of 80% against laboratory-confirmed influenza-associated death among children and adolescents aged 6 months to 17 years.¹ For children with underlying health conditions, vaccine effectiveness against influenza-related hospitalization or emergency department visits was 48%.¹ Maternal vaccination during pregnancy improved protection against symptomatic disease in infants younger than 6 months by 44%, based on data spanning 2011-2022.¹ No new safety concerns emerged among nearly 10 million people evaluated through post-marketing surveillance.¹

COVID-19 protection for infants and young children

Researchers screened more than 11,000 COVID-19 studies and included 155 in the final analysis.¹ Maternal vaccination lowered pregnant patients’ risk of emergency department and urgent care visits by 58% and extended protection to infants, reducing COVID-19-related hospital contacts in the first 2 months of life across a vaccine effectiveness range of 50% to 54%, regardless of gestational timing of the vaccine.¹ Among children aged 9 months to 4 years, vaccination was associated with a 76% reduction in COVID-19-related pediatric emergency department visits.¹ Investigators found no new safety concerns in comparative studies, though post-marketing surveillance data lacking comparison groups could not establish whether adverse events occurred more often than expected without vaccination.¹

RSV immunization and nirsevimab in infants

Of more than 2000 studies assessed, 75 met inclusion criteria for the RSV review.¹ Maternal RSV vaccination reduced infant hospitalization risk by 51% to 70%, while the monoclonal antibody nirsevimab reduced RSV-related hospitalization risk by 63.6% to 93.0% within an infant’s first RSV season, regardless of when it was administered.¹ No comparative study identified an association between maternal RSV vaccination and preterm birth or other adverse pregnancy outcomes.¹ The AAP’s updated RSV policy separately expanded high-risk criteria for infants and children 8 through 19 months entering a second RSV season.²

Context: a review conducted outside a disrupted federal process

The evidence review arrives against a backdrop of disruption at the CDC’s Advisory Committee on Immunization Practices (ACIP), whose members were dismissed and replaced by the Department of Health and Human Services in 2025; a court challenge succeeded in March 2026, but an expert-led ACIP has not been restored.¹ The AAP has continued issuing its own annual immunization schedule independent of CDC guidance during this period.³

Limitations

The review’s authors note that post-marketing safety surveillance data generally lack control groups, limiting causal safety conclusions, and that questions remain open regarding whether older adults need RSV vaccine boosters — a question less directly relevant to pediatric practice but reflective of ongoing evidence gaps across all 3 viruses.¹

References

1. Vaccine Integrity Project, American Medical Association. Vaccine Integrity Project and AMA announce completed independent evidence review of respiratory virus immunizations. Published 2026. Accessed September 2, 2026. https://vaxintegrity.cidrap.umn.edu/2026-27-respiratory-season-evidence-review

2. Committee on Infectious Diseases. Recommendations for the prevention of RSV disease in infants and children: policy statement. Pediatrics. 2026. doi:10.1542/peds.2026-079047

3. American Academy of Pediatrics. Recommended childhood and adolescent immunization schedule: United States, 2026: policy statement. Pediatrics. 2026;157(3):e2025075754.