A sweeping review by the Vaccine Integrity Project (VIP) suggests no new evidence that would prompt the recent changes to fall COVID vaccine recommendations made by HHS.
During a livestreamed meeting, members of the project presented evidence reviews for vaccination against three respiratory viruses in three specific populations: pregnant people, children, and those who are immunocompromised.
“What you heard clearly today are the new data published since CDC’s last evidence review does not indicate the emergence of a new safety signal or a sudden drop in effectiveness,” said Michael Osterholm, PhD, MPH, director of the Center for Infectious Disease Research and Policy (CIDRAP) at the University of Minnesota, which hosts the VIP.
“There is no scientific evidence to support the changes that HHS made to COVID vaccine recommendations for pregnant women or children most at risk,” Osterholm said during the briefing.
Since the beginning of July, the VIP — which includes 24 experts from across the country — has worked to review the evidence that has evolved since the last time the CDC conducted its reviews — known as its Evidence to Recommendations framework — for respiratory virus vaccine recommendations. For COVID, that goes back to Jan. 1, 2024; for influenza, Aug. 26, 2023; and for respiratory syncytial virus (RSV), there was no start date since the vaccines and monoclonal antibody products are so new.
The review was registered on PROSPERO, which describes itself as an “international prospective register of systematic reviews.”
The VIP will not make recommendations itself, but the data will be used by other groups to inform their own recommendations, Osterholm said. For instance, the American Academy of Pediatrics consulted with the VIP in launching its pediatric COVID vaccine recommendations earlier today. (The group previously released its own influenza vaccine recommendations.)
Osterholm noted that analyses for two other populations — older adults and the general population — will be released at a later date.
Ultimately, the entire review will be published in a medical journal, a spokesperson for the VIP told MedPage Today.
For their review, the group screened 17,262 abstracts, with 1,406 undergoing full-text review, and ultimately included 590 studies, 50 of which were randomized controlled trials.
Caitlin Dugdale, MD, MSc, an infectious disease physician at Massachusetts General Hospital and Harvard Medical School in Boston, presented the group’s findings on vaccination in pregnancy.
There were no new data on COVID or RSV vaccine effectiveness (VE) in the publication window, while one influenza study showed a VE of 46% for preventing emergency department and urgent care visits in the 2023-2024 season.
As for protection for children when mom was given an RSV vaccine, one study showed a VE of 70% against hospitalization in the 90 days after birth, and three test-negative studies reported an overall VE of 72% against hospitalization, Dugdale said.
There were no new safety concerns with COVID or flu shots, and earlier concerns about preterm birth with the RSV vaccine were allayed by a new subgroup analysis of the MATISSE trial that suggested women from low- and middle-income countries carried the increased risk of preterm birth. In addition, a U.S. electronic health records study showed no increased risk of preterm birth for vaccinated women, Dugdale reported.
As for pediatric data, Harleen Marwah, MD, a pediatrician at Mass General Brigham for Children and Harvard Medical School, reported that a 2024 study of Pfizer’s COVID vaccine showed a VE of 65% against hospitalization for kids ages 5 to 17 years.
As for RSV, 13 studies of nirsevimab (Beyfortus) showed an effectiveness of 64% to 93% against hospitalization, and for influenza, seven studies showed a VE of 46% to 78% against hospitalization or intensive care unit admission.
She also reported no new safety signals with any of the vaccines.
Finally, Michael Abers, MD, of the Albert Einstein College of Medicine in New York City, presented the review of data on immunocompromised patients.
In general, he said, studies showed that even if vaccines are slightly less effective in these populations, they are still protective on the whole.
One notable finding was that the RSV vaccine seemed to be particularly less effective in patients with bone marrow transplant (a VE of 33% compared with 70% for the immunocompromised population overall). However, Abers said this “still suggests the vaccine is somewhat protective, it’s just not as robust as in other populations.”
As for safety signals, the main concern was with the RSV vaccine Abrysvo, which had a small but statistically significantly increased risk of Guillain-Barre syndrome in immunocompromised patients (incidence rate ratio 2.4, 95% CI 1.5-4.0).
However, Abers warned that this amounted to a small absolute risk, occurring in less than one per 30,000 people vaccinated.
Abers said that eventually, all of the review data will be searchable, in a user-friendly data visualization project. Doctors, researchers, and the public will be able to search by disease, product, patient population, and study domain, to find the specific answers they’re looking for, he noted.
Oliver Brooks, MD, a pediatrician at the Charles R. Drew University of Medicine and Science in Los Angeles, who was recently a member of the CDC’s Advisory Committee on Immunization Practices until HHS Secretary Robert F. Kennedy Jr. removed all members in June, attended the meeting as an invited panelist.
He commended the VIP on their ability to bring “transparency … accountability, and quality control, which leads to the data, which leads to recommendations.”
“Unfortunately,” Brooks said, “we really needed this.”
