What percentage of vaccine recipients will experience an anaphylactic reaction?

It is estimated that for every million doses administered, about one (~0.0001%) will result in an anaphylactic reaction following vaccination. The estimate for mRNA COVID-19 vaccines is slightly higher, at 2 to 5 anaphylactic reactions per million vaccinations given. With proper screening, most providers who administer thousands of vaccines in their lifetimes will never see an anaphylactic reaction.