Robert F. Kennedy Jr., in a raucous three-hour confirmation hearing to become President Donald Trump’s health secretary, again sought to reject accusations that he is “anti-vaccine” while evading questions about whether he would accept the findings of vaccine studies.

Kennedy appeared before the Senate health committee Thursday for his second day of testimony, which featured shouting matches and personal stories from senators recounting experiences with children and patients struggling with severe health problems.

Sen. Maggie Hassan, D-N.H., disclosed that she is the mother of a 36-year old man with cerebral palsy. She assailed Republicans and Kennedy for asserting that the science around autism wasn’t settled.

Her voice breaking, Hassan said she constatly thinks about what she did when pregnant with her son that might have caused his condition.

“So please do not suggest that anybody in this body of either political party doesn’t want to know what the cause of autism is,” she said. “You know how many friends I have with children who have autism?”

The chair of the health committee, Sen. Bill Cassidy, R-La., had pressed Kennedy to disavow past comments promoting discredited links between vaccines and autism, so he could “reassure mothers unequivocally, and without qualification, that the measles and hepatitis B vaccines do not cause autism.”

“If the data is there, I will absolutely do that,” Kennedy said.

Moments later, Sen. Bernie Sanders, I-Vt., asked Kennedy whether COVID vaccines were “successful in saving millions of lives.”

“I don’t know,” Kennedy said. “We don’t have a good surveillance system.”

“That is a very troubling response, because the studies are there,” Sanders said. “Your job is to have looked at those studies as an applicant for this job.”

And for the second day, Kennedy appeared to have little familiarity with the massive health programs he would oversee if confirmed to run the Department of Health and Human Services. Pressed by Hassan, he was unable to identify various aspects of Medicare, the health insurance program for tens of millions of older Americans.

Hassan also followed up on Kennedy’s inaccurate descriptions of Medicaid, the program for low-income people, in his first confirmation hearing Wednesday, asking about his statement that the program is “fully paid for by the federal government.” He initially defended his view, saying “Medicaid is paid for by the federal government, I believe that.” He then conceded that he had “misstated something.”

The panel Kennedy appeared before Wednesday, the Senate Finance Committee, is the one that will vote on whether to send Kennedy’s nomination to the full Senate for a final confirmation vote. Kennedy can lose only three Republican votes and still be confirmed if Democrats remain united in their opposition to him.