Lawmakers Clash With Robert F. Kennedy Jr. as He Shifts Focus Away From Vaccines in Tense Senate Hearing

U.S. Health and Human Services Secretary Robert F. Kennedy Jr. faced sharp questioning from senators during a three-hour hearing on Capitol Hill, repeatedly attempting to redirect the discussion toward chronic disease even as lawmakers pressed him on his shifting vaccine policies. The contentious session underscored the widening rift between the nation’s top health official and members of both parties over immunization policy, staff dismissals, and the direction of the federal health apparatus.

The hearing highlighted the unusual political position Kennedy now occupies. Once a Democratic-aligned environmental attorney and scion of one of America’s most recognizable political families, Kennedy was confirmed as Health and Human Services Secretary in February 2025 after aligning with President Donald Trump’s second-term administration. His confirmation was among the narrowest in recent memory, with Senator Mitch McConnell—a polio survivor—casting the lone Republican vote against him. Since taking office, Kennedy has overseen one of the most significant restructurings of federal public health agencies in decades, including layoffs affecting roughly 10,000 HHS employees and a reorganization that consolidated several agencies under a new Administration for a Healthy America.

Vaccine policy has emerged as the most volatile flashpoint of Kennedy’s tenure. In June, he dismissed the entire Advisory Committee on Immunization Practices, the independent expert panel that has guided U.S. vaccine recommendations since 1964, and replaced its members with appointees who include several vocal vaccine skeptics. The Food and Drug Administration subsequently restricted approval of updated COVID-19 vaccines to adults 65 and older and those with underlying conditions, departing from the universal recommendations that had been in place. Major medical organizations, including the American Academy of Pediatrics and the American College of Obstetricians and Gynecologists, have issued their own guidance that diverges from the administration’s stance—an extraordinary public break between federal health authorities and the medical mainstream.

The timing of the hearing is especially consequential as the country confronts its largest measles outbreak in more than three decades, with more than 1,400 confirmed cases reported across multiple states in 2025 and at least three deaths, including two children in West Texas. Public health experts have attributed the resurgence in part to declining childhood vaccination rates, which have fallen below the 95 percent threshold needed for herd immunity in a growing number of school districts. Kennedy has faced pointed criticism for his measured response to the outbreak, including promotion of vitamin A supplementation, which physicians warn is not a substitute for the MMR vaccine and can cause toxicity when misused.

What comes next is likely to intensify rather than subside. Several senators signaled interest in additional oversight hearings, and at least one bipartisan letter is circulating seeking a formal investigation into the dismissal of CDC leadership. Legal challenges from medical associations contesting the new vaccine recommendations are advancing through federal court, while state health departments—some, like Florida, moving to eliminate vaccine mandates entirely, and others, like California and New York, reaffirming them—are increasingly charting divergent paths. The fractures exposed in the hearing suggest that the coming months will test not only Kennedy’s leadership but also the durability of the post-World War II consensus on federal public health authority.