During a combative appearance before a House committee Wednesday, the health and human services secretary, Robert F. Kennedy Jr., declined to say whether he would vaccinate a child for measles, chicken pox, and polio, saying his views on vaccines are “irrelevant.” 

In his first appearance before Congress since his confirmation hearings in January, Mr. Kennedy fielded questions about recent budget and staff cuts to the Department of Health and Human Services. He also addressed the HHS’s handling of the measles outbreak in Texas and his ongoing crusade against fluoride.

During questioning from Representative Mark Pocan, a Democrat of Wisconsin, Mr. Kennedy shied away from “giving advice” to Americans on whether they should take vaccines. 

“If you had a child today, would you vaccinate that child for measles?” Mr. Pocan asked. 

“Probably for measles. What I would say is my opinions about vaccines are irrelevant,” Mr. Kennedy said in response. 

Mr. Kennedy, who as the top public health official in the country is required to oversee HHS agencies such as the Centers for Disease Control and Prevention and the Food and Drug Administration, added that he “didn’t want to seem like I’m giving advice to other people.”

“But that’s kind of your jurisdiction, because the CDC does give advice, right?” Mr. Pocan replied.

Mr. Kennedy deferred to the National Institutes of Health director, Jay Bhattacharya, to “lay out the pros and cons, risks and benefits, accurately as we understand them with replicable studies.”

At the end of the hearing, Representative Rosa DeLauro, a Democrat of Connecticut, scolded Mr. Kennedy for his earlier response. 

“You have an unbelievable job,” Ms. DeLauro said. “Our job, and your job, is to save lives.”

Facing criticism over his agency’s handling of the measles epidemic, which has now surpassed 800 cases in a number of states such as Texas, Mr. Kennedy defended his agency’s response. “We are doing a better job at the CDC today than any nation in the world in controlling the measles outbreak,” Mr. Kennedy told Congress. 

The hearing began with opening statements from representatives including Ms. DeLauro, who used the opportunity to go after President Trump and a White House advisor, Elon Musk, for “recklessly and unlawfully freezing and stealing congressional appropriated funds from a wide swath of agencies.”

The White House’s proposed 2026 budget calls for $94 billion for the HHS, a nearly 26 percent drop from the 2025 budget. It is also seeking $500 million for the administration’s Make America Healthy Again initiative that targets the “chronic disease epidemic.”

“I cannot thank you for the Trump administration’s budget to cut funding for important health programs by $33 billion. Quite frankly, I view it as a disgrace,” Ms. DeLauro said.

In his opening remarks, Mr. Kennedy said the HHS was committed to delivering more efficient and effective Medicaid and Medicare programs to the 100 million-plus Americans who rely on them while simultaneously reducing costs. He said the HHS would be more aggressive in its response to the opioid and fentanyl crises, and improve food safety efforts through regulation and education to remove “harmful chemicals from food and packaging.” 

Since Mr. Kennedy took office, the HHS has slashed a quarter of its workforce, to just about 62,000 from 82,000, through a combination of layoffs, early retirements, and forced resignations. 

“We intend to do more, a lot more, with less. The budget I’m presenting today supports these goals and reflects two enduring American values: compassion and responsibility,” Mr. Kennedy read from his statement. 

Later in the hearing, Mr. Kennedy defended his decision to phase out petroleum-based artificial food dyes from the food supply. Last week, the FDA approved three new dyes made from natural sources, including butterfly pea flower extract.

“Congressman DeLauro, you say that you’ve worked for 20 years on getting food dyes out? Give me credit. I got it out in 100 days, right? So let’s work together and do something that we all believe in, which is to have healthy kids in our country,” Mr. Kennedy said. 

Representative Chuck Fleischmann, a Republican of Tennessee who represents food manufacturers in his state, defended the use of artificial dyes in mass-produced products like Little Debbie’s Oatmeal Creme Pies. 

“We want to make sure that [the] FDA has done due diligence to ensure the safety of these replacement colors,” Mr. Fleischmann said, adding that incorporating these new colors would increase costs for snack manufacturers. 

Representative Mike Simpson, a Republican of Idaho and a dentist by trade, pressed Mr. Kennedy on the HHS’s decision to remove ingestible products containing fluoride from the market. Previously, Mr. Kennedy and the FDA commissioner, Marty Makary, said the best way to prevent cavities was by “avoiding excessive sugar intake and good dental hygiene, not by altering a child’s microbiome.”

Citing his 22 years as a practicing dentist, Mr. Simpson disagreed with Mr. Kennedy’s comments on fluoride. 

“You don’t prevent cavities by fluoride killing the bacteria in the mouth,” Mr. Simpson said. “What it does is make the enamel more resistant to decay. So, I want to see the studies on this and where we’re headed with this.” 

Later Wednesday, Mr. Kennedy is slated to appear before the Senate Health, Education, Labor, and Pensions Committee to discuss the 2026 HHS budget.