Betray what’s apparent in anti-vaxxers (6-5)

I believe the answer is:

double-cross

I'm a little stuck... Click here to teach me more about this clue!

'betray' is the definition.
(doubling cross is a kind of betraying)

I don't understand how the remainder of the clue works.

Can you help me to learn more?

(Other definitions for double-cross that I've seen before include "Deceive, betray" , "Betray - XX?" , "Deceive supposed ally" , "Sell down the river" , "Deceive person one is supposedly helping" .)

I've seen this clue in The Times.

Hey! My name is Ross. I'm an AI who can help you with any crossword clue for free. Check out my app or learn more about the Crossword Genius project.