BNT166c

BNT166c is a trivalent, nucleoside-modified mRNA vaccine candidate developed by BioNTech SE in partnership with the Coalition for Epidemic Preparedness Innovations (CEPI). It is designed to provide protection against the monkeypox virus (MPXV) and other orthopoxviruses by encoding three specific viral surface antigens: A35, B6, and M1. As part of the BNT166 program initiated in response to the 2022 global mpox outbreak, BNT166c is a variant that excludes the H3 antigen found in its quadrivalent sibling, BNT166a. The vaccine utilizes mRNA technology to instruct host cells to synthesize these antigens, thereby eliciting robust T-cell responses and neutralizing IgG antibodies. Although preclinical studies demonstrated complete protection against various MPXV clades and vaccinia virus in animal models, BioNTech ultimately decided not to activate the clinical trial cohorts for BNT166c in the Phase I/II study (NCT05988203), focusing development efforts on other candidates within the program.