PT - JOURNAL ARTICLE AU - Choi, Angela AU - Koch, Matthew AU - Wu, Kai AU - Dixon, Groves AU - Oestreicher, Judy AU - Legault, Holly AU - Stewart□Jones, Guillaume B.E. AU - Colpitts, Tonya AU - Pajon, Rolando AU - Bennett, Hamilton AU - Carfi, Andrea AU - Edwards, Darin K. TI - Serum Neutralizing Activity of mRNA-1273 against SARS-CoV-2 Variants AID - 10.1101/2021.06.28.449914 DP - 2021 Jan 01 TA - bioRxiv PG - 2021.06.28.449914 4099 - http://biorxiv.org/content/early/2021/06/28/2021.06.28.449914.short 4100 - http://biorxiv.org/content/early/2021/06/28/2021.06.28.449914.full AB - The emergence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants has led to growing concerns over increased transmissibility and the ability of some variants to partially escape immunity. Sera from participants immunized on a prime-boost schedule with the mRNA-1273 COVID-19 vaccine were tested for neutralizing activity against several SARS-CoV-2 variants, including variants of concern (VOCs) and variants of interest (VOIs), compared to neutralization of the wild-type SARS-CoV-2 virus (designated as D614G). Results showed minimal effects on neutralization titers against the B.1.1.7 (Alpha) variant (1.2-fold reduction compared with D614G); other VOCs such as B.1.351 (Beta, including B.1.351-v1, B.1.351-v2, and B.1.351-v3), B.1.617.2 (Delta), and P.1 (Gamma) showed decreased neutralization titers ranging from 2.1-fold to 8.4-fold reductions compared with D614G, although all remained susceptible to mRNA-1273–elicited serum neutralization.Competing Interest StatementA.C., M.K., K.W., G.D, J.O., H.L., G.S.-J., T.C., R.P. H.B., A.C. and D.K.E. are employed by Moderna Inc. and hold equities from the company.