Microphone problem after vocalist session

So I am doing my first tracking session with a real band ever - everything had been laid down except the vocals, so the singer comes in and we lay down a bunch of vocal tracks. Near the end of the recording session, my NT1A starts cutting out at the last tracks, like the sound will be fine for 2 seconds then go real quiet and distorted/noisy for a while when the singer belts out loud lines. The mic put up with this intense, loud screaming for about an hour with no problems before this happened, and I ended up having to switch to a SM57 for him to finish his screaming parts. From the smell of it, the guy basically spat all over my NT1A when he sang (and the windscreen in front of it), so maybe too much moisture got inside? Is my mic ruined? Is there a way to clean it? Anyone have tips on avoiding these problems in the future?

Check some reputed sources on the web for cleaning capsules. It can be a terrifying and ruinous thing to do. Often if the sound cuts then ramps back up, its a cap problem, but those are pretty immune to spit usually. If it is a slobber problem, its time for a finer pop filter, also for screamy stuff, that windsock doesnt hurt the sound any to my ears

If it got moist enough, it could potentially bottom out the capsule

Apparently too many plosives can do that on a NT1A, which may be what happened.