Introduction In the first paragraph of Pfizer document 2.4 NONCLINICAL OVERVIEW, Pfizer states that “BNT162b2 is a nucleoside modified mRNA (modRNA) expressing full-length S [spike] with two proline mutations (P2) to lock the transmembrane protein in an antigenically optimal prefusion conformation” (p. 6, https://www.phmpt.org/wp-content/uploads2022/03/125742_S1_M2_24_nonclinical-overview.pdf). They list two references (Pallesen […]