The federal government is officially back to work, and unfortunately, so is Robert F. Kennedy Jr.’s influence over the country’s public health. Early next month, a panel of outside advisors assembled by Kennedy will meet once again and probably take a sledgehammer to more vaccines.

The Centers for Disease Control and Prevention (CDC) recently posted the draft agenda for the next meeting of its Advisory Committee on Immunization Practices, scheduled for December 4 and 5. Among other things, ACIP plans to discuss the childhood vaccination schedule as well as “contaminants” in vaccines. Though it’s not exactly clear what ACIP will vote on during this meeting, some of its members will likely try to remove the decades-old recommendation that children be vaccinated against hepatitis B starting at birth—a decision that even some GOP lawmakers are trying to prevent.

“I want to make America healthy, and you don’t start by stopping recommendations that have made us substantially healthier,” Senator Bill Cassidy (R-Louisiana) told CBS News’ Face the Nation in an interview released Sunday.

The hijacked ACIP

Earlier this year, Kennedy unilaterally dismissed all 17 members of the ACIP, the panel of outside experts that helps guide the CDC’s vaccine policies. He then quickly added new advisors, many of whom—like Kennedy himself—have a history of spreading misinformation about vaccines.

In its two meetings to date, the rejiggered ACIP has issued several recommendations welcomed by the anti-vaccination movement. It moved to ban the few remaining vaccines that contained thimerosal, for instance, an ingredient that antivaxxers have long accused of causing autism with dubious evidence. Though thimerosal was removed from most vaccines as a precaution in the early 2000s, studies since have failed to find any link to autism, and autism rates have only continued to rise. The ACIP also called for children under four to no longer receive the combination measles, mumps, rubella, and varicella vaccine (MMRV), a decision that the previous CDC had left up to parents.

These decisions, and the ACIP’s general shift away from science-backed evaluation, have helped fuel the internal collapse of the CDC. In late August, RFK Jr. fired former CDC director Susan Monarez just four weeks into her role, reportedly because she refused to sign off on the ACIP’s recommendations without conducting her own review; soon after, much of the CDC’s senior leadership resigned in protest.

So far, the ACIP’s worst decisions have been limited in their scope. Few vaccines today include thimerosal, and most families weren’t vaccinating their very young children with the MMRV shot. But the potential removal of universal at-birth hepatitis B vaccination threatens to be its most sweeping and damaging change yet.

Unscientific fears

Hepatitis B is spread through direct contact with bodily fluids. In adults, it’s usually transmitted via sex or by sharing contaminated needles. But the virus can also be passed from an infected mother to the child during childbirth.

Though a hepatitis B infection can be managed with antivirals if it becomes chronic, there is no curative treatment currently. Most children with hepatitis B will have it for the rest of their lives, and about a quarter will experience serious health problems, including cirrhosis and liver cancer.

Thirty years ago, ACIP and the CDC began to recommend that everyone receive the hepatitis B vaccine when young, eventually moving towards at-birth dosing for the first shot. This strategy was only adopted after previous attempts to just vaccinate the highest-risk groups failed to significantly lower cases. And since its implementation, rates of hepatitis B, especially in children, have steadily fallen in the U.S. The vaccine is also safe, with its most serious side effects, like anaphylaxis, being exceptionally rare and manageable with proper monitoring.

At the last ACIP meeting in September, CDC staff argued in support of at-birth vaccination and warned that more children would almost certainly develop hepatitis B if the policy was removed. Both sessions of the ACIP ran long, and at the very last minute—amidst lots of confusion about what the members were actually voting on—the ACIP unexpectedly chose to table its planned vote on hepatitis B. Given the inclusion of hepatitis B on Friday’s agenda, however, it appears that reprieve was short-lived.

The inclusion of the childhood vaccine schedule on Thursday’s agenda is also plenty concerning. Antivaxxers have made no secret about their desire to tear the schedule to shreds if they could. The Children’s Health Defense, the anti-vaccination group founded by RFK Jr., hosted its “Moment of Truth” conference earlier this month. During the conference, Mark Gorton, president of the MAHA Institute—a group founded to bolster Kennedy’s “Make America Healthy” movement—called for the “childhood vaccination schedule to be eliminated.”

As before, the reformed ACIP has not revealed the contents of its votes scheduled for this next meeting. So it’s still up in the air just how far its members will go in trying to change the schedule. But there’s certainly no reason to be optimistic about what lies ahead for the country’s public health under the reign of RFK Jr.