This story was originally produced by the New Hampshire Bulletin, an independent local newsroom that allows NHPR and other outlets to republish its reporting.
In a visit to Concord Friday, U.S. Health Secretary Robert F. Kennedy Jr. cast doubt on the safety of the hepatitis B vaccine but wouldn’t comment on state legislation in New Hampshire that his agency inspired.
In June 2025, Kennedy fired every member of the Centers for Disease Control and Prevention’s Advisory Committee on Immunization Practices, a panel of experts that creates national vaccine guidance, and subsequently replaced them with fellow vaccine skeptics. His new handpicked members ultimately rolled back the federal government’s guidance on the hepatitis B vaccine, among other immunizations. The panel voted that December to rescind the recommendation that infants receive the hepatitis B shot at birth unless the mother tested positive for the virus. However, the federal government’s vaccine schedule is just a recommendation. State governments enact requirements.
In New Hampshire earlier this year, state Rep. Kelley Potenza used the change as justification to similarly roll back New Hampshire’s hepatitis B vaccine requirement.
“New Hampshire has always followed, like I said before, the ACIP and CDC guidance on vaccines until now,” Potenza, who has long tried to eliminate state vaccine requirements, said in January. “This bill continues the tradition by aligning state law with the ACIP’s and the CDC’s updated hepatitis B recommendation.”
Asked if this was his intention or if he believed it was a positive development, Kennedy said it was ACIP’s decision and “the hepatitis B vaccine has been used for many years since 1991, but we don’t know what the risk profile is for that product because there was no randomized placebo-controlled trial prior to its licensure.”
However, according to the Center for Infectious Disease Research and Policy at the University of Minnesota, that’s not true. As early as 1980, a double-blind study published in the New England Journal of Medicine enrolled 1,083 subjects and randomized them to receive the vaccine or placebo and a subsequent study took place in 1984 in Hong Kong. CIDRAP argues that many who make this claim do so because no randomized placebo-controlled trials were cited in the Food and Drug Administration filing. However, that doesn’t mean that reputable scientists have never conducted trials. Specifically, it excludes those that were published in peer-reviewed journals but weren’t listed in a particular regulatory submission, per CIDRAP.
“Normally, we would not license a medical product without pre-licensing safety testing,” Kennedy continued.
Potenza’s bill — House Bill 1719 — was passed in the House but stifled by the Senate, which voted to continue studying the issue before taking any more action. Other anti-vaccine bills debated this year tried to eliminate nearly all vaccine requirements in New Hampshire outright (House Bill 1811), simplify the process for parents to request exemptions on religious grounds (House Bill 1022) and forbid state agencies from advertising vaccines (House Bill 1616).
On the federal level, Kennedy has elevated the growing anti-vaccine movement in the United States and been sharply condemned by the mainstream medical community throughout his tenure as health secretary. He and President Donald Trump have also cut hundreds of millions in funding for mRNA vaccine research for influenza, COVID-19 and other diseases, and they’ve fired roughly 10,000 federal health employees, though courts have halted some of his moves over questions on process and legal authority.
