Top CDC Vaccine Adviser Challenges Critics to Debate

Martin Kulldorff said former Centers for Disease Control and Prevention directors should engage in an ‘open and honest’ debate with him.

Martin Kulldorff, chair of the Advisory Committee on Immunization Practices, speaks during a committee meeting at the Centers for Disease Control and Prevention headquarters in Atlanta on June 25, 2025. Mike Stewart/AP Photo

The top outside vaccine adviser for the Centers for Disease Control and Prevention (CDC) on Sept. 18 called on critics to debate him.

As the Advisory Committee on Immunization Practices (ACIP) opened its second meeting since being restructured, the committee’s chair, Martin Kulldorff, said that members of the public who are wondering whom to trust in the current discussions about vaccines should “only trust scientists who are willing to engage with and publicly debate the scientists with other views.”

“With such debates, you can weigh and determine the scientific reasoning by each side,” Kulldorff said. “But without it, you cannot properly judge their arguments.”

Kulldorff directly challenged the nine former CDC directors—including Dr. Mandy Cohen, the last director during the Biden administration—who wrote in a recent op-ed that new ACIP members are unqualified and hold “dangerous and unscientific views.”

Kulldorff is an epidemiologist who developed several programs that are used by health officials to monitor the safety of vaccines.

He worked with the CDC for years before he was removed in 2021 as a member of an ACIP subgroup because he advocated for keeping Johnson & Johnson’s COVID-19 vaccine available after the CDC paused its administration. Officials lifted the pause a short time later, although the shot was ultimately pulled from the market.

Kulldorff pointed to his past work, including dozens of articles he co-authored with government and university scientists. Most of the studies did not identify any problems with vaccines.

“By dismissing us as unscientific, the former CDC directors are de facto questioning not only us and our scientific research, but they are also questioning the safety of many childhood vaccines that we have shown to be safe,” he said. “The fact is that we are honest vaccine scientists that let the data speak whether the results go in one direction or the other. That is always how science should operate.”

‘Pro-Vaccine Agenda’

Health and Human Services Secretary Robert F. Kennedy Jr. in June appointed Kulldorff and others, including vaccine inventor Dr. Robert Malone, to the advisory committee after removing all 17 existing members.

In the first meeting of the remade panel, in June, ACIP approved continuing the annual influenza vaccine recommendation. It also voted to advise officials to remove thimerosal, a mercury-based preservative that has been linked to health problems, from flu vaccines.

“This committee strongly supports the use of vaccines, and other countermeasures, predicated on evidence-based medicine, including rigorous evaluation and expansive, credible scientific data, for both safety and efficacy,” the new members said in a joint statement at the time.

Kulldorff said on Sept. 17 that ACIP members are “committed to reassuring the public and restoring public confidence by removing unnecessary risks and harms whenever possible,” which he said is “the pro-vaccine agenda.”

Various countries have different vaccine schedules; only one Nordic country recommends hepatitis B vaccination at birth, and some countries do not recommend it at all. Votes at this week’s meeting, which are scheduled to include a vote on the U.S. recommendation that infants receive a hepatitis B shot shortly after birth, will reflect that variability, Kulldorff said.

“We welcome scientific critique of any of our votes, as there are gray areas due to incomplete scientific knowledge,” he said. “But, false accusations that we and other respectable vaccine scientists are unscientific and dangerous anti-vaxxers, that just adds legitimacy to anti-vax positions, damaging both public health and the confidence in vaccines. Such false accusations are only logical if their purpose is political.”

Kulldorff reiterated his view that people should only trust scientists willing to debate other scientists who have different views. He said that if the nine former CDC directors who authored the op-ed decline to engage in a live, public debate with him on vaccines, then he will advise people to “not trust them.”

Kulldorff extended the same invitation to Susan Monarez, who was recently fired as director of the CDC, and the top CDC officials who then resigned.

Dr. Tom Frieden, a former CDC director who is now president and CEO of Resolve to Save Lives, said in an emailed statement that he is “open to a reasonable discussion.”

A lawyer representing Monarez did not immediately respond to a request for comment. Other former CDC directors for whom contact information could be found did not immediately return inquiries.

During the COVID-19 pandemic, Kulldorff engaged in public debates, including one about vaccine mandates with Dr. Paul Offit, who backs all current vaccine recommendations and opposes religious exemptions to vaccine mandates.

Harvard Medical School fired Kulldorff in 2024 for declining to receive a COVID-19 vaccine.

Monarez testified before a Senate panel on Sept. 17 that she was fired after she refused Kennedy’s demands that she fire CDC scientists and that she preapprove recommendations from ACIP. Kennedy has said that Monarez told him that she was untrustworthy and that she had committed to not approving ACIP’s recommendations.

“I was open to the science,” Monarez said. “I just would not precommit to approving all the ACIP recommendations without the science.”