The article states,

"...abotegravir – a component of Cabenuva – was 89% more effective in preventing infection among women than Truvada"

That 89% when was compared to Truvada.

Do healthcare workers actively take Prep or is it administered within the 72 hour period after exposure?

Prep from what I understand can be hard on the body's organs and you will need to do a kidney function test every few months when on it