By The Associated Press

During his Senate confirmation hearings, Health Secretary Robert F. Kennedy Jr. suggested he wouldn’t undermine vaccines.

“I am not going to go into HHS and impose my preordained opinions on anybody at HHS,” he said. “I’m going to empower the scientists at HHS to do their job and make sure that we have good science that is evidence based.”

He also said he wouldn’t halt congressionally mandated funding for vaccination programs, nor impose conditions that would force local, state or global entities to limit access to vaccines or vaccine promotion.

“I’m not going to substitute my judgment for science,” he said.

Yet the Department of Health and Human Services under Kennedy has taken unprecedented steps to change how vaccines are evaluated, approved and recommended — sometimes in ways that run counter to established scientific consensus.

Here’s a look at what Kennedy has said and done since becoming the nation’s top health official on Feb. 13.

Kennedy and the childhood vaccine schedule

Sen. Bill Cassidy, a physician who was unsettled about Kennedy’s antivaccine work, said Kennedy pledged to him that he wouldn’t change existing vaccine recommendations.

“I recommend that children follow the CDC schedule. And I will support the CDC schedule when I get in there,” Kennedy said at his Senate confirmation hearing.

Kennedy also said he thought the polio vaccine was safe and effective and that he wouldn’t seek to reduce its availability.

Feb. 18: Kennedy vows to investigate the childhood vaccine schedule that prevents measles, polio and other dangerous diseases.

Early March: The National Institutes of Health cancels studies about ways to improve vaccine trust and access.

April 9: Kennedy tells CBS News that “people should get the measles vaccine, but the government should not be mandating those,” before then continuing to raise safety concerns about vaccines.

May 22: Kennedy issues a report that, among other things, questioned the necessity of mandates that require children to get vaccinated for school admission and suggested that vaccines should undergo more clinical trials, including with placebos. The report has to be reissued later because the initial version cited studies that don’t exist.

May 30: The Centers for Disease Control and Prevention removes COVID-19 vaccination guidance for pregnant women and says healthy children “may” get the shots.

June 25: A group of vaccine advisers picked by Kennedy announce they are establishing a work group to evaluate the “cumulative effect” of the children’s vaccine schedule.

June 25: Kennedy announces the U.S. will stop supporting the vaccines alliance Gavi. He accuses the group, along with the World Health Organization, of silencing “dissenting views” and “legitimate questions” about vaccine safety.

Kennedy on revising CDC vaccine recommendations

At the confirmation hearing, Cassidy asked Kennedy: “Do you commit that you will revise any CDC recommendations only based on peer review, consensus based, widely accepted science?”

Kennedy replied, “Absolutely,” adding he would rely on evidence-based science.

Feb. 20: HHS postpones a meeting of outside vaccine advisers.

April 16: The CDC’s vaccine advisory panel meets and recommends that people 50 to 59 with certain risk factors should be able to get vaccinated against respiratory syncytial virus, and endorses a new shot that protects against meningococcal bacteria. As of late June, the CDC and HHS haven’t acted on the recommendations.

May 27: Kennedy announces that COVID-19 vaccines are no longer recommended for healthy children and pregnant women — a move immediately questioned by several public health experts. No one from the CDC, the agency that makes such recommendations, is present in the video announcing the changes.

June 9: Kennedy ousts all 17 members of the science panel that advises the CDC on how vaccines should be used.

June 11: Kennedy names new vaccine policy advisers to replace the panel that he dismissed. They include a scientist who rose to prominence by relaying conspiracy theories around the COVID-19 pandemic and the vaccines that followed, a leading critic of pandemic-era lockdowns, a business school professor, and a nurse affiliated with a group that is widely considered to be a leading source of vaccine misinformation.

June 26: Kennedy’s vaccine advisers recommend that people receive flu shots free of an ingredient that antivaccine groups have falsely tied to autism. The vote comes after a presentation from an antivaccine group’s former leader. A CDC staff analysis of past research on the topic is removed from the agency’s website because, according to a committee member, the report hadn’t been authorized by Kennedy’s office.

Kennedy on vaccine approvals and review standards

At the Senate hearing, Cassidy asked Kennedy if he would keep FDA’s historically rigorous vaccine review standards.

“Yes,” Kennedy replied.

March 29: Kennedy forces the FDA’s top vaccine official to resign. The official, Peter Marks, says he feared Kennedy’s team might manipulate or delete data from a vaccine safety database.

May 6: Kennedy names Dr. Vinay Prasad, an outspoken critic of the FDA’s handling of COVID-19 boosters, as the FDA’s vaccine chief.

May 16: After a delay, the FDA grants Novavax full approval for its COVID-19 vaccine but with unusual restrictions: The agency says it’s for use only in adults 65 and older – or those 12 to 64 who have at least one health problem that puts them at increased risk from COVID-19.

May 20: Top officials limit the approval for seasonal COVID-19 shots to seniors and others at high risk, pending more data on everyone else. The FDA urges companies to conduct large, lengthy studies before tweaked vaccines can be approved for healthier people, a stark break from the previous federal policy recommending an annual COVID-19 shot for all Americans six months and older.

May 30: FDA approves a new COVID-19 vaccine made by Moderna but with the same limits on who can get it as Novavax’s shot.

Kennedy on bird flu vaccine

At his confirmation hearing, Kennedy said he would support the development of a vaccine for H5N1 bird flu.

“I’m going to continue research on every kind of vaccine,” he said.

May 28: The Biomedical Advanced Research and Development Authority, an HHS agency, cancels $766 million in awards to Moderna to develop a vaccine against potential pandemic influenza viruses, including the H5N1 bird flu.

The Associated Press Health and Science Department receives support from the Howard Hughes Medical Institute’s Science and Educational Media Group and the Robert Wood Johnson Foundation. The AP is solely responsible for all content.