WASHINGTON — Heidi Overton, President Donald Trump’s nominee to lead the Food and Drug Administration, told senators Thursday that vaccines currently available in the United States are safe and effective, directly rejecting Trump’s recent description of the measles, mumps and rubella vaccine as “quite lethal.” Overton said the MMR vaccine is safe and effective and urged people to get it as the United States confronts its largest measles outbreak in more than 30 years. Nearly 6,000 people have been affected in an outbreak that began 19 months ago, with four reported deaths associated with the infection. Her testimony is part of a broader pattern among nominees to the Department of Health and Human Services: several have affirmed vaccine safety during Senate confirmation proceedings, despite Health Secretary Robert F. Kennedy Jr.’s history of questioning vaccines and his plans to scale back some federal recommendations. The Senate Health, Education, Labor and Pensions Committee’s chair, Sen. Bill Cassidy, a Louisiana Republican and vaccine advocate, pressed Overton on Trump’s comments. Cassidy also cited surgeon general nominee Nicole Saphier, who told senators last week she did not consider the MMR vaccine lethal and called it the most important tool for fighting measles. Cassidy praised her answer. Chris Klomp, nominated to be deputy health secretary, has also endorsed the measles vaccine. At his confirmation hearing, he called vaccination the best way to eradicate the disease and said he had seen no evidence the shot causes autism. The Senate Finance Committee voted Thursday to advance his nomination to the floor, with all committee Republicans and one Democrat, Sen. Sheldon Whitehouse of Rhode Island, supporting it. The Senate has confirmed Erica Schwartz as director of the Centers for Disease Control and Prevention after she endorsed vaccination. Two other nominees, Klomp and Sean Kaufman, nominated to lead the Administration for Strategic Preparedness and Response, are awaiting floor votes. Kaufman previously questioned vaccine safety and said he would rather die than vaccinate his children against Covid-19. At his confirmation hearing, he said he now considers vaccines safe and effective and an important public-health tool. The administration withdrew the nomination of Casey Means for surgeon general in April after she failed to secure enough support among Republicans on Cassidy’s committee. Means said vaccination saves lives but argued parents should decide about it with their doctors. Measles can cause serious complications, including pneumonia and encephalitis, or brain swelling. Government data show two doses of the measles vaccine are 97% effective at preventing the disease. Rare adverse reactions do occur: federal estimates put anaphylaxis at roughly two to 14 cases per million doses, while febrile seizures have been associated with about one in 3,000 to 4,000 doses and typically do not cause lasting harm. No credible research has linked the MMR vaccine to autism. Public statements in favor of vaccines do not guarantee that nominees would oppose Kennedy’s efforts to reduce recommended vaccinations if confirmed. Cassidy told Overton he wanted assurances about how she would handle ethical questions in the role. The dispute has also extended to how the CDC counts measles deaths: the agency is working with a national epidemiologists’ group on a standardized definition after Kennedy challenged the attribution of some recent Pennsylvania deaths to measles.