On June 26th, the Department of Health and Social Services’ (HSS) newly restructured Advisory Committee on Immunization Practices (ACIP) made several decisive votes. The most prominent among them was the recommendation for Merck’s respiratory syncytial virus (RSV) monoclonal antibody drug, clesrovimab, and turning down a constituent in certain flu vaccines. The drug Clesrovimab is recommended for infants under eight months of age and became the second FDA-approved RSV preventive therapy for young children after its approval in early June. It followed AstraZeneca’s Beyfortus (nirsevimab-alip), which received FDA approval in July 2023 for children aged 24 months or younger.
In addition to these recommendations, the panel voted 5-1, with one abstention, in favor of single-dose influenza vaccines devoid of the preservative thimerosal. Introduced in the 1930s in small doses to fight bacterial contamination, thimerosal became controversial due to its mercury-based formulation. However, despite research not finding a correlation between the preservative and harmful effects, most vaccine manufacturers phased it out in 1999, as per the Centers for Disease Control and Prevention (CDC).
These recommendations are among the first significant actions taken by the newly instated ACIP, which saw a complete overhaul approximately two weeks ago when all 17 members of ACIP were replaced by the HSS. The abrupt change, according to HSS Secretary Robert F. Kennedy Jr., aimed to enhance public trust and wasn’t driven by any specific vaccination agenda. This sudden shift, however, sparked a contra reaction from multiple national healthcare organizations.
As its mandate suggests, ACIP is an independent panel that reviews vaccine-related data and offers guidance to the CDC. It is noteworthy that the CDC is under no obligation to abide by the panel’s advice, but it usually does. In the committee’s first meeting post formation, several ACIP members thoroughly scrutinized the CDC’s data collection procedures, especially those pertaining to vaccine safety metrics.
The vote on Clesrovimab, originally scheduled for June 25, was deferred until the morning of June 26 due to internal deliberations. The voting concluded with five ‘yes’ votes and two ‘no’. A day prior to the new panel’s meeting, a committee member, Dr. Micheal Ross, withdrew from the panel during a ‘financial holdings review’, as confirmed by an HSS spokesperson. In a parallel recommendation for the flu vaccines, six members voted with one abstention to reinforce the previous ACIP guidance on promoting routine yearly inoculations for adults and children older than six months.
The vote against thimerosal noticed five panelists opposing the preservative with one supporting it and the last one abstaining. Cody Meissner, MD, a professor of pediatrics at Dartmouth College’s Geisel School of Medicine, was the sole dissenter. Prior to the vote, he deliberated whether the elimination of the preservative was necessary, stressing the lack of scientific evidence of harm due to thimerosal.
The article was updated on June 26 to illustrate the ACIP vote on thimerosal until this report.