It's not even applicable to most vaccines.

Basically polio spreads through poop, and this is your shedding. Oral Polio Vaccine does this as it's a weakened form of the polio virus and exhibits the same spread and provides vaccination indirectly to others. The US uses E-IPV, which is inactive and harmless and doesn't have this spread.

You'll only find OPV being used in countries with very inadequate medical access as it can be administered orally(hence the name). Only downside is that if you are very immunocompromised, there is a non zero chance you get polio and a chance you suffer from paralysis.

Flu vaccines, covid vaccine, literally anything else doesn't have this "shedding". It's literally one vaccine that isn't even administered in the united states.

Yes, pay attention to mention of "shedding". They think that vaccination causes the PT in question to shuck it off as though they were Pigpen from Charlie Brown cartoon.

Yes.

Well, the grifters don't. The multitude of morons they're scamming do.

Stupid as it sounds, yes

https://www.politifact.com/article/2021/may/06/debunking-anti-vaccine-hoax-about-vaccine-shedding/

Vaccines can shed (sometimes we have to add that as an seondqry endpoint to clinical trials), but not even remotely in the way these idiots are saying.

Were you assuming these people understood even the basics of what a vaccine is?