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.