President Donald Trump’s nominee for deputy health secretary, Chris Klomp, testified before the Senate on Sept. 15 that he supports the measles, mumps, rubella (MMR) vaccine as a critical public health tool, while fielding questions about his role in negotiating drug pricing agreements with pharmaceutical companies.
Klomp, currently chief counselor at the Department of Health and Human Services, was nominated to serve as assistant health secretary pending Senate confirmation. During his confirmation hearing, he stated that the MMR vaccine is the most effective public health measure against measles, adding that he does not believe it is linked to autism based on available evidence. He also declined to endorse the influenza vaccine with the same level of certainty.
The hearing also addressed Klomp’s involvement in the Trump administration’s “most favored nation” drug pricing deals, which have been negotiated with more than two dozen pharmaceutical companies. Sen. Elizabeth Warren (D-Mass.) pressed him on the transparency of these agreements, demanding detailed documentation of the negotiations.
Klomp confirmed that Robert F. Kennedy Jr., the health secretary and a vocal vaccine skeptic, supported his nomination despite their policy disagreements. Kennedy has previously suggested potential links between vaccines and autism, citing disputed studies, while Klomp’s testimony aligned with mainstream scientific consensus.
Measles cases in the U.S. have risen since early 2025, reaching levels not seen since 1991, according to Sen. Ron Wyden (D-Ore.), who questioned Klomp about Kennedy’s public statements on vaccines. Wyden also highlighted concerns over Kennedy’s claims about the MMR vaccine’s ingredients, including assertions that it contains aborted fetal tissue—a reference to historical cell line usage in vaccine development.
Klomp’s testimony underscored the administration’s divided stance on vaccines, with Kennedy’s skepticism contrasting with his deputy’s endorsement of established public health measures. The Senate Finance Committee is expected to vote on Klomp’s confirmation in the coming weeks.