Tonight on PBS News Weekend, a former top CDC vaccine expert explains why she resigned in protest and why she fears that changing vaccine recommendations could cost lives.

Then how artificial intelligence is helping scientists track the wide-ranging migration patterns

of humpback whales. And in our hidden history series, pioneering comedian and activist

Robin Tyler, who used humor to campaign for LGBTQ rights and fight homophobia.

Humor is the razor sharp edge of the truth.

It's pain and anger made funny.

So in order to make a joke, you have to believe in it. 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 hand-picked 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 longstanding recommendations for flu shots containing thimerosol,

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 Rogan. 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? The dismissal of the committee 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

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