This study demonstrates that a recombinant prefusion-stabilized spike (rS) protein vaccine based on Beta/B.1.351 (rS-Beta) produces a robust anamnestic response in baboons against SARS-CoV-2 variants when given as a booster dose after immunization with NVX-CoV2373. rS-Beta is highly immunogenic in mice and produces neutralizing antibodies against WA1/2020, Beta/B.1.351, and Omicron/BA.1. Mice vaccinated with NVX-CoV2373 or rS-Beta alone, in combination, or heterologous prime-boost, are protected from challenge. The rS-Beta vaccine alone or in combination with rS-WU1 induces antibody- and cell-mediated responses protective against SARS-CoV-2 variants and offers broader neutralizing capacity than rS-WU1 prime/boost alone. These data suggest a Beta variant booster dose could elicit a broad immune response to fight new and future SARS-CoV-2 variants.

James Logue, Robert M. Johnson, Nita Patel, Bin Zhou, Sonia Maciejewski, Bryant Foreman, Haixia Zhou, Alyse D. Portnof, Jing-Hui Tian, Asma Rehman, Marisa E. McGrath, Robert E. Haupt, Stuart M. Weston, Lauren Baracco, Holly Hammond, Mimi Guebre-Xabier, Carly Dillen, M. Madhangi, Ann M. Greene, Michael J. Massare, Greg M. Glenn, Gale Smith, Matthew B. Frieman