Robert F Kennedy Jr. is set to have his first hearing Wednesday as President Donald Trump's nominee for secretary of Health and Human Services in which his answers to questions about vaccinations are expected to play a key role in whether he is confirmed to the post. 

To be sure, the debate over vaccinations, particularly government-mandated ones, and whether their risks of side effects outweigh their usefulness in preventing people from contracting potentially deadly illnesses, has divided Americans over the past several decades. 

The issue became front and center in the U.S. over COVID-19 vaccine mandates, resulting in a passionate and largely partisan disagreement that continues today. 

Kennedy will appear Wednesday before the Senate Committee on Finance, which will ultimately be the committee with the deciding vote on whether his nomination to be the next HHS secretary advances to the full Senate, in which Republicans have a 53-47 seat majority.

He must receive yes votes from a majority of senators to be confirmed to lead HHS, which encompasses the country's federal health agencies. The committee's jurisdiction largely focuses on the department's Medicare and Medicaid health insurance programs for seniors and low-income Americans, which make up the largest share of mandatory spending in the federal budget, according to CBS News.

Kennedy on Thursday will go before the Senate Committee on Health, Education, Labor and Pensions, whose focus is on the Centers for Disease Control and Prevention, the Food and Drug Administration and the National Institutes of Health, all agencies that would fall under Kennedy's authority if he is confirmed to lead the department, CBS also reports. 

Kennedy is the founder of Children's Health Defense, a nonprofit that seeks to prevent childhood health epidemics caused by environmental toxins. The safety of COVID vaccines, the effects of MMR immunizations, and early childhood vaccine schedules are among the issues addressed by the group. Kennedy also produced the CHD documentaries Vaxxed, Vaxxed II, and Vaxxed III.  

Kennedy has also been outspoken in questioning the safety of certain vaccines outside of CHD including in his 2014 book Thimerosal: Let the Science Speak: The Evidence Supporting the Immediate Removal of Mercury - a Known Neurotoxin - from Vaccines and his 2023 book Vax-Unvax: Let the Science Speak.  

Other public health-related topics that Kennedy has been outspoken on leading up to his nomination include creating stricter food and drug ingredient regulations and removing fluoride from public water supplies.

Some health organizations have criticized Kennedy's nomination due to his history of questioning the safety of specific vaccines and vaccine ingredients.  

A group of 87 state and national public health groups, including ACA Consumer Advocacy, signed a January 24 petition asking the Senate not to confirm Kennedy, an environmental lawyer. The signers both referenced his beliefs about vaccines in the petition and included signatures from pro-vaccine groups.

Kennedy's views on vaccines have sparked optimism for some, who hope he will implement reforms at a time when public trust in health agencies is lower than in the past. A recent survey conducted by CHD and referenced in a press release earlier this week found that over a third of moderate voters no longer trust federal health agencies and that 59% of all voters trust the CDC and FDA. 

The Kaiser Family Foundation also released similar survey findings with 53% of all participants saying that they trust the FDA and 61% saying that they trust the CDC. KFF also found that trust in the HHS is at 55% overall and that 43% of all participants say that they trust Kennedy. 

Kennedy, who ran in the 2024 presidential campaign as a Democrat, then as an independent, is expected to have a mostly negative reception from Democrats. However, he has received some limited positive comments from former fellow Democratic Party members such as Tim Ryan, who wrote a December 2024 oped in Newsweek urging Democrats to work with Kennedy on food reforms.

"We have a rare chance to fix a system that is literally killing us," Ryan said.  "We are a sick country, and a sick country cannot maintain long-term prosperity. Kennedy is passionate about this issue, and he's willing to take on the entrenched interests that have perpetuated this broken system for decades. Democrats should join him in this fight."

While he has the support of most of the Senate GOP conference, Sens. Mitch McConnell, of Kentucky, Lisa Murkowski, of Alaska, Susan Collins, of Maine, Thom Tillis, of North Carolina, John Curtis, of Utah and Bill Cassidy, of Louisiana, are potential no votes, enough to sink Kennedy's nomination bid, according to reports from The Associated Press.