On June 26, HSS’ newly formed Advisory Committee on Immunization Practices voted 5-2 to recommend Merck’s respiratory syncytial virus monoclonal antibody drug and against an ingredient in some flu vaccines.
The RSV drug in question, clesrovimab, is recommended for infants younger than 8 months. It was approved in early June, making it the second FDA-approved RSV preventive therapy for young children. The first, AstraZeneca’s Beyfortus (nirsevimab-alip), received FDA approval in July 2023 for children 24 months and younger.
The panel also voted 5-1, with one abstaining, to recommend single-dose influenza vaccines without the ingredient thimerosal. Thimerosal, a preservative, was introduced in doses in the 1930s to combat bacterial contamination. While research has failed to find a link between the mercury-based preservative and evidence of harm, most vaccine-makers removed the ingredient in 1999, according to the CDC.
The committee’s recommendations mark one of the first major actions by the newly appointed ACIP, which underwent a complete overhaul about two weeks ago when HHS removed all 17 members of ACIP.
HHS Secretary Robert F. Kennedy Jr. said the abrupt change was for the “restoration of public trust above any specific pro- or anti-vaccine agenda.” The move sparked backlash from several national healthcare organizations.
ACIP is an independent panel that reviews vaccine information and provides guidance to the CDC, which does not have to follow the panel’s recommendation but often does. During the first day of the committee’s two-day meeting, several ACIP members repeatedly questioned the CDC’s data collection practices, particularly regarding vaccine safety metrics.
Originally scheduled for June 25, the vote on clesrovimab was delayed to the morning of June 26. Five members voted “yes” and two voted “no.” Notably, a day before the new panel met, panelist Michael Ross, MD, withdrew from the committee during a required “financial holdings review,” according to an HHS spokesperson.
Regarding flu vaccines, six members voted, and one abstained, to reaffirm previous ACIP guidance on recommending routine annual inoculations for adults and children older than 6 months. For thimerosal, five panelists voted against the preservative, one voted in favor and another abstained.
The single dissenting vote was Cody Meissner, MD, a professor of pediatrics at Dartmouth College’s Geisel School of Medicine in Hanover, N.H. Before the vote, he questioned whether removing the preservative was necessary.
“The ACIP makes recommendations based on scientific evidence as much as possible,” Dr. Meissner said. “There is no scientific evidence that thimerosal has caused a problem … To make the industry jump through hoops for something for which there is no evidence of harm, I think, is an issue that needs further discussion.”
Editor’s note: On June 26, this article was updated to include the ACIP vote on thimerosal.
