Both Republicans and Democrats clash with RFK Jr. on vaccines, CDC turmoil

Sen. Bernie Sanders took aim at Kennedy's statements casting doubt on the integrity of major medical organizations. Kennedy argued they've been corrupted by the pharmaceutical industry.

"You're telling the American people that the American Medical Association, representing hundreds of thousands of people, have been coopted and that they should not trust their doctors? And the American Academy of Pediatrics? And by the way, just for the record, every single Republican -- I don't mean to be political here, Mr. Chairman -- has received PAC money from the pharmaceutical industry. Are they all corrupt as well?" Sanders asked.

Kennedy doubled down, telling Sanders: "I'm telling you, the American Heart Association has been corrupted by the pharma industry."

Sanders later fired back, "To suggest that every institution, the AMA, the pediatrics people, is 'corrupt' because they disagree is an insult."

In a fiery exchange with Sen. Elizabeth Warren, a Democrat from Massachusetts, Kennedy claimed the recently fired CDC Director Susan Monarez said she was not trustworthy.

Warren pointed to an op-ed Monarez wrote for The Wall Street Journal on Thursday saying she wouldn't prematurely sign off on recommendations from the CDC's vaccine advisory committee.

"I told her that she had to resign because I asked her, 'Are you a trustworthy person?' And she said, 'No,'" Kennedy replied. "If you had an employee who told you they weren't trustworthy, would you ask them to resign, senator?"

Kennedy reiterated the statement when asked by Sen. Bernie Sanders, an independent from Vermont, about the exchange with Monarez.

"Are you telling us that the former head of CDC, you asked her, 'Are you a trustworthy person?' And she said, 'No, I am not a trustworthy person,'" Sanders asked.

'"She didn't say, 'No, I'm not a trustworthy person.' She said, 'No,'" Kennedy replied.

Bernie Sanders, the independent senator from Vermont, suggested he will bring ousted CDC director Susan Monarez to Capitol Hill to testify.

"I look forward to her coming before the HELP Committee, maybe this committee as well," Sanders said.

Kennedy claimed that anyone can get COVID-19 vaccines at their pharmacy for free, however, pharmacies are being selective due to the limbo of federal regulations.

The FDA has approved the updated shots for only older and high-risk Americans, and the CDC vaccine panel is set to meet to discuss potential recommendations in a few weeks.

Amid the regulatory uncertainty, some pharmacies have said that access to the shots may vary state-by-state and may require a prescription.

-ABC News' Youri Benadjaoud