RaTG13, a close relative of SARS-CoV-2, shares high genomic similarity. This study investigated whether antibodies from SARS-CoV-2 infection or vaccination neutralize RaTG13. Surprisingly, RaTG13 was more efficiently neutralized than SARS-CoV-2 by convalescent sera. Neutralization assays using spike mutants revealed that both spike proteins tolerate multiple changes without significantly impacting neutralization. The E484K mutation increased RaTG13 neutralization but decreased SARS-CoV-2 neutralization. These findings suggest current SARS-CoV-2 vaccination strategies might mitigate future RaTG13 spillover.

Diego Cantoní, Martin Mayora-Neto, Nazia Thakur, Ahmed M. E. Elrefaey, Joseph Newman, Sneha Vishwanath, Angalee Nadesalingam, Andrew Chan, Peter Smith, Javier Castillo-Olivares, Helen Baxendale, Bryan Charleston, Jonathan Heeney, Dalan Bailey, Nigel Temperton