JOHN YANG: Good evening, I'm John Yang.

Health Secretary Robert F. Kennedy Jr's influence on the government's approach to vaccines began to emerge this week when his handpicked advisory panel held its first meeting.

The committee pushed for a review of the entire childhood vaccine schedule, a reevaluation of hepatitis B vaccinations for babies, and walked back the long standing recommendations for flu shots containing thimerosal, a preservative that's long been the target of anti-vaccine movement.

Earlier this month, Kennedy fired all 17 members of the vaccine panel, which is called the Advisory Committee on Immunization Practices, or ACIP.

He then named eight new members, at least half of whom have expressed skepticism about some vaccines.

That prompted the resignation of Dr. Fiona Havers, one of the CDC's leading vaccine experts.

She discussed your decision with Ali Rogin.

ALI ROGIN: Dr. Havers, thank you so much for joining us.

You've said that you contemplated resigning from your post several times since Secretary Kennedy was confirmed.

Why is it that the dismissal of the entire vaccine advisory panel really the last straw for you?

DR. FIONA HAVERS, Infectious Disease Physician: The dismissal of the committee and 17 and the firing of the 17 experts was really the last straw for me because it really showed that they were planning on blowing up the whole process.

I think that the ACIP recommendations process is very regimented and evidence based.

The committee is very carefully vetted.

And when he just fired everyone on the committee and then replaced them with handpicked people that many of whom are really not qualified to be on sitting on this committee, I had no faith anymore that this process would use scientific evidence to make informed policy decisions.

ALI ROGIN: So at this last meeting of this panel, they voted on something that had not been on the agenda, the removal of the preservative thimerosal from vaccines.

So what does this all mean to you in terms of the flouting of very well established, up until this point, procedure with approving the childhood vaccine schedule and other norms?

FIONA HAVERS: No, that's a great question.

And it was really remarkable that they moved forward with this vote.

I think historically, if there's going to be a vote on a policy proposal, it requires months of preparation, a formal process and a review of evidence by a workgroup that then presents to the voting members.

What they did at this meeting was that they had a singles presentation from someone who introduced herself as a private citizen, and then they move forward immediately to a vote to change policy that potentially restricts access to certain types of vaccines that have been previously viewed as safe and effective.

And regardless of the topic of the vote, which is a separate question, the fact that they didn't follow any of these procedures for systematic review of the evidence, that is the ACIP norms, is very concerning.

So the entire direction that this is heading shows that RFK Jr. has taken over the ACIP and CDC recommendation process.

And this is a really important process because if a vaccine is recommended by ACIP and officially added to the CDC immunization schedule, it determines whether insurance will cover it.

In addition, ACIP votes on what's included in the Vaccine for Children's program, which provides free vaccines to more than half of children in the United States.

So what I'm seeing is a dismissal of the normal, very rigorous, evidence based process that ACIP usually goes through and basically RFK Jr. pushing forward anti-vaccine agenda while bypassing all of this sort of normal, rigorous science based processes that have been put in place to ensure transparency and good vaccine policy.

ALI ROGIN: You've said that one of the first alarm bells for you that led up to your decision to resign was the misleading citation that you say of some data that you presented.

I want to play a clip for you.

This is a top FDA official comparing COVID hospitalization rates among young children versus older adults.

MAN: This is cumulative COVID 19 hospitalization by age 50 to 64.

It's approximately 55 per 100,000 over the last season.

And 1 to 4 is 20 per 100,000.

If you go down to 0 to 4, it's 30 per 100,000.

ALI ROGIN: How is this a misrepresentation of your data?

FIONA HAVERS: So the problem is that he lumped all children under four into the same age group and only presented hospitalization rates for 0 to 4 or 1 to 4 as a group.

But there's a huge difference in the risk of serious COVID disease in an infant compared to a healthy four year old.

And these were precisely the data that the hospitalization system that I oversaw before I left CDC, which these numbers come from, were being evaluated by the COVID ACIP Work Group for a much more nuanced discussion of what COVID vaccination policy should be in children.

And you know, the following week after unassists, they had this that showed that video RFK Jr. announced on X the CDC no longer recommended COVID vaccines for healthy children and healthy pregnant women.

And so it's very possible that had this process been able to work itself out properly.

The ACIP work group would have come to different recommendations about vaccinating a healthy baby who is, you know, six months of age or older, who's eligible for the primary vaccination series.

They may have voted for something different for a healthy four year old who's had COVID before.

So I think that, you know, he presented data from the network that I was overseeing, but he missed all of the nuance that we had been working to present to the ACFU Work Group and then at the public meeting at which are important nuances when you're making vaccine policy for millions of children.

ALI ROGIN: Dr. Fiona Havers, thank you so much for joining us.

FIONA HAVERS: Thank you for having me on.