And given that precise numbers like 93% is meaningless. One should either give the range or at least describe the population.
And it turned out 93% was not coming from the study in https://www.pnas.org/content/pnas/118/12/e2026153118.full.pd..., they just reference https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5863094/ , but that nowhere mention the number 93% and it’s abstract give much more sensible data:
Delivery of the two doses of vaccine needed to achieve >90% immunity is accomplished by routine immunization of infants at 9–15 months of age followed by a second dose delivered before school entry or by periodic mass vaccination campaigns. B