While some presentations at this week's ACIP meeting appear to be business-as-usual, others seem to regurgitate settled safety topics around flu shots and the combination measles, mumps, rubella and varicella vaccine.
With controversial presentation topics on the docket and the already abbreviated panel suddenly down one member, this week’s meeting of the CDC’s Advisory Committee on Immunization Practices (ACIP) is shaping up to be a long, strange two days.In opening Wednesday’s meeting, newly appointed ACIP chair Martin Kulldorff, Ph.D., leaned into the controversy surrounding U.S. vaccine policy following the COVID-19 pandemic and, more recently, Robert F. Kennedy Jr.’s ascension to the top of HHS.“Some media outlets have been very harsh on the new members of this committee, issuing false accusations and making concerted efforts to put scientists in either a pro- or anti-vaccine box,” Kulldorff explained. “Such labels undermine critical scientific inquiry, and it further feeds the flames of vaccine hesitancy.”He highlighted the need for ACIP and other appendages of the federal health apparatus to rebuild public trust and confidence, which he argued has reached an “all-time low” following the alleged mishandling of the COVID-19 pandemic.“If you think that all vaccines are safe and effective and want them all, or if you think that all vaccines are dangerous and don’t want any of them, then you don’t have much use for us,” Kulldorff said. “But if you wish to know which vaccines are suitable for you and your children and at what ages, then we will provide you with evidence-based recommendations.”He stressed that Kennedy “has given this committee a clear mandate to use evidence-based medicine when making vaccine recommendations, and that is what we will do.”However, while some presentations of the two-day meeting appear to be business-as-usual, others seem to regurgitate “long-settled safety topics” around the mercury-containing flu vaccine preservative thimerosal and the combination measles, mumps, rubella and varicella (MMRV) shot, Richard Hughes IV, a health lawyer at Epstein Becker Green, wrote in an emailed preview of the event.One of the presentations (PDF) targeting thimerosal—slated for Thursday—originally cited a study of dubious provenance, with one of the study’s listed co-authors denying that the data reflect his work, according to Reuters. Since the initial release of presentation materials on Tuesday, the CDC has since uploaded a new version of the presentation that removes the study citation, the news service reports. Meanwhile, several sections on the docket, including the deliberations around COVID-19 and respiratory syncytial virus (RSV) vaccines, “appear rushed or procedurally incomplete,” Hughes said. The issue could stem from a pause in work group meetings after Kennedy abruptly fired all 17 of ACIP’s sitting members earlier this month, he added.Kennedy quickly slotted in eight picks of his own for the panel. However, in another unexpected turn for this week’s meeting, one of the new appointees—Michael Ross, M.D.—has withdrawn from the vaccine advisory group, The New York Times first reported Tuesday.“Dr. Michael Ross decided to withdraw from ACIP during the financial holdings review required of members before they can start work on the committee,” an HHS spokesperson told Fierce Pharma. “The sacrifice to serve on ACIP varies from member to member, and we appreciate Dr. Ross’s willingness to go through this rigorous process,” he said, adding that the panel would have benefited from Ross’ service and expertise.Ross, who previously served on the CDC’s Advisory Committee for the Prevention of Breast and Cervical Cancer, is no longer listed among the voting ACIP members on the CDC’s website. Packed agendaOver the next two days, ACIP is slated to review the safety and effectiveness of vaccines for COVID-19, RSV, influenza, chikungunya, anthrax and MMRV. The panel will only vote on recommendations for maternal and pediatric RSV vaccines and flu shots.Given the lack of a vote on the COVID vaccine issue, recent limitations to CDC immunization policies for healthy kids and pregnant people are “unlikely to change,” said health lawyer Hughes. Although the planned presentations on COVID vaccines outline evidence of the shots’ benefits, the data are “juxtaposed with adverse events slides … which could be used to validate the recent policy change,” he explained.Safety concerns will factor into the panel’s vote on material and pediatric RSV immunizations, too, with Hughes pointing out that presentation slides highlighting pregnancy-related safety signals could be used by the new ACIP members “as a justification for recommendation change at this meeting or in the future.”The same issue is also at play in the reviews of chikungunya and MMRV vaccines, with the latter shot subject to scrutiny over a potential increased risk of febrile seizures following an initial dose in kids between the ages of 12 and 23 months.Although the overall evidence being presented on MMRV vaccines “affirms a favorable safety profile,” the presentation also “elevates older studies showing a modest seizure risk in infants” who received the quadruple combination shot over a measles, mumps and rubella vaccine and a separate varicella shot, Hughes said. Targeting thimerosalIt is Thursday’s review of influenza vaccines, however, that is likely to prove the most controversial during the two-day ACIP meeting. The agenda starts out relatively par for the course, with Sanofi planning to present immunogenicity and safety data for a recombinant flu shot in kids, followed by a separate presentation on the 2024-25 flu season and proposed recommendations.However, the panel is then slated to review data on thimerosal—a mercury-containing preservative used in certain adult flu vaccines—which has been inaccurately linked to the development of autism spectrum disorder (ASD). The ingredient was removed from most childhood vaccines in the early 2000s and there is little evidence to suggest it poses safety concerns, Bloomberg News noted in a report last week.To hear Hughes tell it, the thimerosal data—which are being presented by former Children’s Health Defense president Lyn Redwood—lean “heavily on outdated or misrepresented evidence … to argue that thimerosal is unsafe and ineffective.” Children’s Health Defense, whose stated mission revolves around “ending childhood health epidemics by eliminating toxic exposure,” was founded by Kennedy. As of early Wednesday morning, the presentation material list for this week’s ACIP meeting also included a separate CDC background document that Hughes noted “directly refutes many of the claims related to thimerosal and neurodevelopmental disorders including autism.” But by about 11:00 a.m. ET on Wednesday, the document was not clickable on the CDC’s meeting materials page.Adding to the controversy, Redwood’s original presentation appeared to cite a study that doesn’t exist, according to Reuters. The study, dubbed "Low-level neonatal thimerosal exposure: Long-term consequences in the brain,” was published in the journal Neurotoxicology in 2008 with a co-author credit from University of California, Davis, professor emeritus Robert Berman, according to the original ACIP meeting materials issued Tuesday.But Berman told Reuters emphatically that the presentation is “not making reference to a study I published or carried out,” explaining that he co-authored a similarly named study in a different journal that came to different conclusions than the ones Redwood aimed to present.Berman added that he does “not endorse this misrepresentation of the research," according to Reuters.The slide citing the Berman study is no longer listed in the ACIP meeting materials, Reuters pointed out.In his opening remarks, ACIP chair Kulldorff argued that opposing potentially dangerous ingredients doesn’t make someone inherently opposed to immunizations.“As Secretary Kennedy has eloquently stated, opposing mercury in fish does not make you anti-fish, and opposing mercury in vaccines does not make you anti-vaccine,” he said, echoing the HHS chief.Kulldorff likened vaccine safety to that of airlines, noting that if one airline ignores safety concerns and crashes, there is a knock-on effect for other companies.“The same is true for vaccines,” he said. “When there are unexpected adverse reactions concerning the safety of one vaccine, that affects all other vaccines, reducing vaccine uptake and coverage.” Doctors, lawmakers and scientists reactAmid the vaccine scrutiny taking place this week, the American Medical Association (AMA) and 78 medical societies voiced their support for immunizations on Wednesday as “the best way to protect against the flu, COVID-19, and RSV and their potentially serious complications.”“Recent changes to federal immunization review processes raised concerns across the medical and public health community,” the letter states. “In this moment of uncertainty, physicians must align around clear, evidence-based guidance for patients.” Since Kennedy’s dismissal of the prior ACIP roster, the 17 ousted members have themselves struck back against the decision, penning a recent JAMA editorial that argued Kennedy’s “destabilizing” decision to purge to committee “may roll back the achievements of U.S. immunization policy, impact people’s access to lifesaving vaccines, and ultimately put U.S. families at risk of dangerous and preventable illness.”Meanwhile, earlier this week, Sen. Bill Cassidy, M.D., R-La.—who reportedly pressed Kennedy for promises not to disrupt vaccine policy in exchange for a confirmation vote earlier this year—called for this week’s meeting to be postponed.Cassidy’s concerns came down to the newly appointed ACIP panel, with the Senator arguing that the meeting should be delayed “until the panel is fully staffed with more robust and balanced representation—as required by law—including those with more direct relevant expertise.”