ACIP Votes Against Thimerosal Vaccines for Prevention of Influenza
ACIP also discusses COVID-19 epidemiology as well as safety and efficacy for the COVID-19 vaccines.
In a vote of 5 to 1 on Thursday, members of the Advisory Committee on Immunization Practices (ACIP) voted to recommend against influenza vaccine containing the preservative thimerosal. The recommendations include all US adults as well as recommending pregnant women also receive a thimerosal-free vaccine for influenza. Earlier the same week, a CDC report found there was no connection between thimerosal in vaccines and autism or other neurodevelopmental conditions.1,2
ACIP also discusses COVID-19 epidemiology as well as safety and efficacy for the COVID-19 vaccines. | Image Credit: REDPIXEL - stock.adobe.com
Thimerosal is a mercury-containing compound that has been widely used as a preservative in some biological and drug products, such as promoting the safe use of multidose vials and packaging of vaccines. It is often thought to be used in some seasonal and pandemic influenza vaccines.2
“Mercury is the third most toxic element on earth, only behind polonium and plutonium and has no physiological role in the human body,” Lyn Redwood, RN, MSN, FP, said in an ACIP meeting.1 “There is also evidence that thimerosal is not an effective preservative at vaccine levels.”
Further, Martin Kulldorff, PhD, an epidemiologist and biostatistician, said that people cannot completely avoid exposure to mercury because there is exposure to mercury from other sources. He added that mercury is a cumulative exposure, so even if the exposure from vaccines is safe, exposure from other sources would add up, potentially making these levels unsafe for patients.1
As for other recommendations, the committee voted 6 to 0 to recommend all Americans aged 6 months and older to receive an annual influenza vaccine. For respiratory syncytial virus, ACIP voted to recommend clesrovimab-cfor (Enflonsia) as an option to prevent RSV lower respiratory tract disease for infants younger than 8 months who are born during or entering their first RSV season.1,3
The day prior, ACIP took to discussions about COVID-1, which was highly awaited due to confusion surrounding the upcoming 2025-2026 respiratory season. Although there was no vote related to vaccination, members discussed COVID-19 epidemiology as well as safety and efficacy for the COVID-19 vaccines.4
“The latest recommendations over the past couple weeks have created confusion, and we have seen individuals, as opposed to advisory groups or committees, independently changing vaccine policy. This, coupled with the lack of transparency, is unprecedented and concerning,” said Lauren Angelo, PharmD, MBA, associate dean of academic affairs at Rosalind Franklin University of Medicine and Science.5
Previously, Secretary of Health and Human Services Robert F. Kennedy, FDA Commissioner Marty Makary, MD, MPH, and the National Institutes of Health (NIH) Director Jay Bhattacharya, MD, PhD, released a video on X, stating that healthy children and healthy pregnant women were removed from the CDC’s recommended immunization schedule. The recommendation was inconsistent on the CDC website.6
In the ACIP meeting, Adam MacNeil, PhD, MBA, deputy branch chief for epidemiology in the respiratory viruses branch of the CDC, acknowledged that 89% of children who were eligible for the COVID-19 vaccine and were hospitalized with the virus had no record of receiving the most recently recommended COVID-19 vaccines.4
“The majority of children hospitalized with COVID-19 in October 2024 to March 2025 did not receive the most recently recommended COVID-19 vaccine,” he said.4 “Roughly 10% of children across all pediatric age groups have received their recommended COVID-19 [20]24-[20]25 dose.”
In the presentation, data from 131 hospitalized pregnant women with COVID-19 showed that 50% had no underlying conditions and 92% had no record of vaccination since July 1, 2023, with only 5.8% receiving the recommended 2024-2025 COVID-19 vaccine.4
