Neutralizing Antibody Responses After Severe Acute Respiratory Syndrome Coronavirus 2 BA.2 and BA.2.12.1 Infection Do Not Neutralize BA.4 and BA.5 and Can Be Blunted by Nirmatrelvir/Ritonavir Treatment

Aaron F Carlin; Alex E Clark; Aaron F Garretson; William Bray; Magali Porrachia; AsherLev T Santos; Tariq M Rana; Antoine Chaillon; Davey M Smith

doi:10.1093/ofid/ofad154

Neutralizing Antibody Responses After Severe Acute Respiratory Syndrome Coronavirus 2 BA.2 and BA.2.12.1 Infection Do Not Neutralize BA.4 and BA.5 and Can Be Blunted by Nirmatrelvir/Ritonavir Treatment

Open Forum Infect Dis. 2023 Mar 21;10(4):ofad154. doi: 10.1093/ofid/ofad154. eCollection 2023 Apr.

Authors

Aaron F Carlin¹, Alex E Clark¹, Aaron F Garretson¹, William Bray¹, Magali Porrachia¹, AsherLev T Santos², Tariq M Rana¹, Antoine Chaillon¹, Davey M Smith^{1

3}

Affiliations

¹ School of Medicine, University of California San Diego, La Jolla, California, USA.
² Department of Public Health, College of Education, Health and Human Services, California State University San Marcos, San Marcos, California, USA.
³ VA San Diego Healthcare System, San Diego, California, USA.

Abstract

The factors contributing to the rapid emergence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) BA.4 and BA.5 subvariants in populations that experienced recent surges of BA.2 and BA.2.12.1 infections are not understood. Neutralizing antibodies (NAbs) are likely to protect against severe disease if present in sufficient quantity. We found that after BA.2 or BA.2.12.1 infection, NAb responses were largely cross-neutralizing but were much less effective against BA.5. In addition, individuals who were infected and treated early with nirmatrelvir/ritonavir (Paxlovid) had lower NAb levels than untreated individuals.

Keywords: COVID-19; Omicron; neutralizing antibodies; nirmatrelvir/ritonavir; reinfection.