The White House on Thursday withdrew the nomination of Dr. Dave Weldon, a Republican and former congressman, to lead the Centers for Disease Control and Prevention just hours before he was to have appeared at a Senate confirmation hearing.
Reached by phone, Dr. Weldon said he had learned of the decision on Wednesday night and had been told by a White House official that “they didn’t have the votes to confirm” his nomination.
In a statement released later on Thursday, Dr. Weldon, 71, blamed Senator Susan Collins, Republican of Maine and a member of the Senate health committee, and Senator Bill Cassidy, Republican of Louisiana and the committee’s chairman, for torpedoing his nomination.
A spokesman for Mr. Cassidy said the senator had been “looking forward” to the confirmation hearing. Ms. Collins’s office disputed Dr. Weldon’s account.
“I did not express concerns to the White House. I had some reservations, but I certainly had not reached a final judgment,” Ms. Collins said Thursday.
The withdrawal of Dr. Weldon’s nomination, which followed concerns raised during a meeting on Tuesday with Republican Senate aides, is a significant setback for Robert F. Kennedy Jr., the new secretary of health and human services.
Dr. Weldon and Mr. Kennedy have known each other for 25 years, and both share a deep skepticism of the federal regulatory approach to vaccine safety.
Mr. Kennedy is also confronting a measles outbreak in West Texas, and has drawn criticism for promoting treatments like vitamin A and cod liver oil, and describing vaccination as a personal choice with unknown risks.
The decision to withdraw the nomination was first reported by Axios.
It was unclear if the White House had a backup candidate. The C.D.C. is currently run by an acting director, Dr. Susan Monarez, who previously served as the deputy director of a newly formed biomedical research agency.
In an interview on Thursday, Dr. Weldon said he had been excited by the prospect of serving his country again and helping to restore the public’s confidence in the C.D.C.
He said had also been looking forward to working with Mr. Kennedy on the MAHA, or Make America Healthy Again, agenda to curtail chronic diseases among Americans.
“It is a shock, but, you know, in some ways, it’s relief,” Dr. Weldon said. “Government jobs demand a lot of you, and if God doesn’t want me in it, I’m fine with that.”
The Senate Committee on Health Education, Labor and Pensions canceled Dr. Weldon’s hearing but advanced to the full Senate two other nominees: Dr. Jayanta Bhattacharya to lead the National Institutes of Health and Dr. Martin Makary to head the Food and Drug Administration.
(The hearing for Dr. Mehmet Oz, the nominee to run the Centers for Medicare and Medicaid Services, is scheduled for Friday.)
The abrupt withdrawal appeared to stem from events that took place on Tuesday, when Dr. Weldon met with Republican Senate staff members. In the statement, Dr. Weldon said that aides to Ms. Collins were “suddenly very hostile” at the meeting, despite his “very pleasant” meeting with her two weeks earlier.
Dr. Weldon said the aides were “repeatedly accusing me of being anti-vax.” But Ms. Collins’s office said that was untrue, and that aides had simply asked Dr. Weldon how he would respond to allegations that he opposed vaccination.
According to one person who attended the meeting, and spoke on condition of anonymity to share details, aides were concerned that Dr. Weldon seemed ill-prepared for the job and that he did not have a vision for the C.D.C.
On Wednesday, the day after the meeting, Mr. Kennedy had breakfast with Ms. Collins, Dr. Weldon said. He said Mr. Kennedy informed him that Ms. Collins had expressed reservations about him.
Dr. Weldon was perhaps the least known of the men nominated to lead major agencies at the Department of Health and Human Services. But he was the one aligned most closely with Mr. Kennedy.
The health secretary has cited Dr. Weldon’s criticisms of the C.D.C. along with his own. Mr. Kennedy is “very upset” at the decision to withdraw the nomination, Dr. Weldon said.
“I’m going to get on an airplane at 11 o’clock and I’m going to go home and I’m going to see patients on Monday,” Dr. Weldon said. “I’ll make much more money staying in my medical practice.”
His hearing had been set to take place amid significant measles outbreaks in Texas and New Mexico, which have infected more than 250 people and claimed two lives; a flu season that led to record numbers of hospitalizations; and the potential for a bird flu epidemic.
He has repeatedly questioned the safety of the measles vaccine and criticized the C.D.C. for not doing enough to prove that vaccines are safe.
“They never did it the right way,” he said in the statement. He also praised the work of the discredited British doctor Andrew Wakefield, who wrongly proposed that vaccines cause autism.
“We might be able to do research and figure out why some kids have a bad reaction” to the measles-mumps-rubella vaccine, Dr. Weldon wrote, despite dozens of studies that have disproved a link. “Clearly, Big Pharma didn’t want me in the C.D.C. investigating any of this.”
Dr. Weldon served in Congress for 14 years, from 1995 to 2009. During his tenure, he pushed to move the vaccine safety office away from C.D.C. control, saying the agency had a conflict of interest because it also purchases and promotes vaccines.
Dr. Weldon is also a staunch opponent of abortion.
His signature legislative accomplishment was the Weldon Amendment, which bars health agencies from discriminating against hospitals or health insurance plans that choose not to provide or pay for abortions.
Like Mr. Kennedy, he had questioned the need to immunize children against hepatitis B, describing it as primarily a sexually transmitted disease afflicting adults.
He also argued that abstinence is the most effective way to curb sexually transmitted infections. Cases have soared in recent years and only began to show signs of a possible downturn in 2023.
In an interview with The New York Times in late November, Dr. Weldon said that he had worked “to get the mercury out of the childhood vaccines.”
The C.D.C. had published a research study showing the mercury had done no harm, “but there were credible accusations that C.D.C. had incorrectly manipulated the data to exonerate themselves,” he said in the statement.
“If confirmed, I was planning on going back into the C.D.C. database and quietly investigate this claim,” he said.
Still, he described himself as a supporter of vaccination. Both his adult children are fully immunized, he said in November. As a doctor in coastal Florida, he said, he prescribes thousands of doses of flu and other vaccines to his patients.
“I’ve been described as anti-vaccine,” Dr. Weldon said, adding: “I give shots. I believe in vaccination.”
