Shares of vaccine maker Moderna sold off to the tune of 5.5% on Tuesday after Robert F. Kennedy Jr., President Donald Trump's nominee to lead the Department of Health and Human Services, cleared a hurdle from the Senate Finance Committee - which voted along party lines to send Kennedy's nomination to the full senate.

Kennedy cleared the committee after Sen. Bill Cassidy (R-LA), voted for him despite raising previous reservations about the selection.

"I’ve had very intense conversations with Bobby and the White House over the weekend and even this morning," Cassidy said in a statement posted to X before the vote. "I want to thank VP JD specifically for his honest counsel. With the serious commitments I’ve received from the administration and the opportunity to make progress on the issues we agree on like healthy foods and a pro-American agenda, I will vote yes."

Last week, Cassidy - a physician, looked like he was a 'no,' grilling RFK over his vaccine stance and demanding that Kennedy renounce his anti-vaccine activism. Kennedy declined, prompting intense discussions between the two over the weekend.

Prior to entering politics, Cassidy was a gastroenterologist who created a program to vaccinate nearly 36,000 children in and around Baton Rouge, Louisiana. During his first three terms in the House, he pushed for increased funding for vaccinations in a majority-black district that spans Baton Rouge to Shreveport. He also pushed the COVID-19 vaccine, which Kennedy once described as "the deadliest vaccine ever made."

Kennedy was grilled in two days of committee hearings last week, while it's unclear whether he has the votes for passage in the Senate, even with Republicans' 53-47 majority.

As far as Moderna and other vaccine makers - it seems they aren't feeling so well these days.