Major evidence review confirms influenza, COVID-19 and RSV vaccines are safe and effective
A major new review finds that vaccination continues to protect against severe illness and hospitalisation, with no new safety concerns.
- 9 September 2026
- 5 min read
- by Linda Geddes
At a glance
- An updated evidence review by the Vaccine Integrity Project and American Medical Association provides reassurance that immunisation remains a safe and effective way of reducing the impact of influenza, COVID-19 and RSV.
- The review also assessed the risks posed by these viruses, finding that they continue to cause substantial numbers of hospitalisations and deaths, particularly among infants, older adults and other vulnerable groups.
- The findings have fed directly into 2026–2027 respiratory virus immunisation recommendations issued by leading US medical associations.
As winter virus season approaches in the northern hemisphere, countries are ramping up efforts to protect people against influenza, respiratory syncytial virus (RSV) and COVID-19.
For those weighing up whether to get vaccinated, a new evidence review sets out the benefits and potential risks of vaccination, and how these compare with catching the diseases themselves.
Published by the University of Minnesota’s Vaccine Integrity Project, and drawing on systematic reviews of hundreds of studies, the review concludes that vaccination against all three viruses provides important protection against severe illness, hospitalisation and death, while serious vaccine-related harms are rare.
It also provides a timely reminder of the health risks of remaining unprotected against these viruses, particularly for vulnerable groups.
Why did the Vaccine Integrity Project review influenza, RSV and COVID-19 vaccines?
This independent review was conducted to ensure that US vaccination recommendations are grounded in the latest scientific evidence, and to help people make informed decisions about getting vaccinated against the three leading causes of serious respiratory virus-related illness in the US.
Researchers at the Vaccine Integrity Project and American Medical Association worked with medical and public health organisations to identify key questions about influenza, COVID-19 and RSV immunisation and evaluate emerging evidence, building on a 2025–2026 evidence review of these vaccines.
This involved screening thousands of studies, with 299 included in the final analysis; most of them published between August 2025 and June 2026.
The review therefore provides an up-to-date picture of vaccine effectiveness and safety, as well as the health risks posed by flu, RSV and COVID-19.
How safe and effective are current vaccines for influenza, COVID-19 and RSV?
Influenza
For influenza, the review found that seasonal vaccination continued to provide important protection against severe disease, particularly for those at greatest risk.
Among adults aged 65 years and over, vaccination was 31% effective against flu-related hospitalisation during the 2025–2026 season. New evidence also suggested that protection against hospitalisation was greater when older adults were offered high-dose flu vaccines versus standard-dose ones.
Among children aged 6 months to 17 years with underlying health conditions, vaccination was 48% effective against flu-related hospitalisation or emergency department visits, while an analysis spanning eight influenza seasons found vaccination was 80% effective against flu-related deaths among children.
Influenza vaccination during pregnancy was 44% effective at preventing symptomatic influenza in babies during their first six months of life.
COVID-19
Updated COVID-19 vaccines similarly continued to provide meaningful protection against hospitalisation, intensive care admission and death, particularly among people at greatest risk of severe disease.
Among older adults, vaccination was 53% effective against COVID-related hospitalisation, while among immunocompromised adults it was 32–53% effective against intensive care admission or death.
COVID-19 vaccination during pregnancy lowered the risk of emergency department and urgent care visits for pregnant women by 58%, as well as resulting in fewer COVID-related hospital contacts for their babies during their first two months of life.
Among children aged nine months to four years, vaccination reduced COVID-related hospital visits by 76%.
RSV
RSV vaccines substantially reduced severe illness among older adults, cutting RSV-related hospitalisation by 69–83% during the same season in which they were given.
However, questions remain over how long protection from RSV vaccination lasts in older adults, and whether booster doses may eventually be needed.
Vaccination during pregnancy reduced the risk of infants being hospitalised with RSV by 51–70%, while the monoclonal antibody nirsevimab reduced infants’ risk of hospitalisation by 64–93% during their first RSV seasons.
On safety, the updated evidence was reassuring, with no new safety concerns identified for any of the vaccines.
Have you read?
How dangerous are the influenza, COVID-19 and RSV viruses?
Although patterns of respiratory illness have changed since the COVID-19 pandemic, the review found that influenza, COVID-19 and RSV continue to cause substantial illness, hospitalisation and death, particularly among infants, older adults, pregnant women and people with weakened immune systems.
During the 2025–2026 season, influenza resulted in at least 390,000 hospitalisations and 24,000 deaths in the US. COVID-19 was associated with an estimated 140,000–240,000 hospitalisations and 15,000–42,000 deaths, while RSV caused an estimated 170,000–340,000 hospitalisations and up to 25,000 deaths.
What message should people take from this report?
Taken together, the findings provide reassurance that vaccination remains a safe and effective means of reducing the impact of respiratory viruses.
They have also fed directly into 2026–2027 respiratory virus immunisation recommendations released by the American Academy of Pediatrics, American Academy of Family Physicians, American College of Obstetricians and Gynecologists and Infectious Diseases Society of America.
“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,” said Vaccine Integrity Project Executive Director Michael T. Osterholm.
