| President Donald Trump's press conference last month about autism created a firestorm of controversy about the over-the-counter painkiller Tylenol. The hubbub overshadowed that he also revealed a new frontier in his administration’s moves to change how childhood vaccines are formulated and administered. “We want no aluminum in the vaccine,” Trump said during the White House press conference, surprising even some ardent anti-vaccine activists. A panel of experts that advises the Centers for Disease Control and Prevention on vaccine policy is taking the first steps toward implementing the president’s directive. The panel, the Advisory Committee on Immunization Practices, said in a new document it may study whether either of two aluminum adjuvants in childhood vaccines increase the risk of asthma. An adjuvant is an ingredient used to boost the effects of a shot. The CDC says that aluminum salts, used to strengthen the body’s immune system, “have been used safely in vaccines for decades.” Vaccines that contain aluminum adjuvants primarily include products made by GSK, Merck & Co., Pfizer and Sanofi. They are used to inoculate children and adults against diseases including polio, hepatitis A and B, human papillomavirus, diphtheria, tetanus, pertussis, meningitis and pneumonia. Health Secretary Robert F. Kennedy Jr. has a history of blaming aluminum in vaccines for various ailments, including depression, anxiety, allergies and Alzheimer’s disease. There’s no evidence to support his claims. The CDC says vaccines that use adjuvants can cause more redness and pain at the injection site and more side effects like fever and chills than ones that don’t include them. The CDC also cites one observational study from 2022 that showed a possible relationship between aluminum exposure from vaccines and asthma, and says “further investigation is needed.” A larger 2023 study conducted by Denmark’s public health agency found no association between aluminum adjuvants and asthma. Kennedy demanded that the Annals of Internal Medicine medical journal retract the Danish study, but the editors of the journal refused. Paul Offit, director of the Vaccine Education Center at Children’s Hospital of Philadelphia, said that aluminum adjuvants are used so clinicians can offer greater effectiveness with fewer doses of a vaccine. Kennedy has attacked Offit, who previously served on the CDC vaccine advisory panel, publicly over his role in developing a rotavirus vaccine. “There is abundant evidence that aluminum in vaccines is harmless,” Offit says. “If you live on the earth’s surface, you are going to be exposed to aluminum.” Kennedy fired all the members of ACIP this summer and appointed new members, including vaccine critics. The panel’s next meeting, scheduled for October, has been delayed, and it’s unclear when it will be rescheduled and whether its next meeting will include any policy or research presentations related to aluminum adjuvants. — Rachel Cohrs Zhang | 
