The neutralizing response to SARS-CoV-2 Omicron variants BA.1 and BA.2 in COVID-19 patients and homologous and heterologous vaccinees

• Published in: Human vaccines & immunotherapeutics Vol. 18; no. 6; p. 2129196
• Main Authors: Dapporto, Francesca, Leonardi, Margherita, Trombetta, Claudia Maria, Semplici, Claudia, Piu, Pietro, Piccini, Giulia, Benincasa, Linda, Marchi, Serena, Andreano, Emanuele, Lovreglio, Piero, Buonvino, Nicola, Decaro, Nicola, Stufano, Angela, Lorusso, Eleonora, Bombardieri, Emilio, Ruello, Antonella, Viviani, Simonetta, Rappuoli, Rino, Molesti, Eleonora, Manenti, Alessandro, Montomoli, Emanuele
• Format: Journal Article
• Language: English
• Published: United States Taylor & Francis 30.11.2022; Taylor & Francis Group
• Subjects: Antibodies, Neutralizing; Antibodies, Viral; Brief Report; Coronavirus – Brief Report; COVID-19 - prevention & control; Humans; hybrid immunity; mrna booster; neutralizing antibodies; omicron ba.1; omicron ba.2; Patients; sars-cov-2; SARS-CoV-2 - genetics; sars-cov-2 vaccines; Hybrid immunity; Omicron BA.1; mRNA booster; SARS-CoV-2; Omicron BA.2; SARS-CoV-2 vaccines; neutralizing antibodies
• ISSN: 2164-5515; 2164-554X; 2164-554X
• DOI: 10.1080/21645515.2022.2129196

The rapid replacement of Omicron BA.1 by BA.2 sublineage is very alarming, raising the question of whether BA.2 can escape the immunity acquired after BA.1 infection. We compared the neutralizing activity toward the Omicron BA.1 and BA.2 sub-lineages in five groups: COVID-19 patients; subjects who had received two doses of mRNA vaccine; subjects naturally infected with SARS-CoV-2 who had received two doses of mRNA; and subjects who had received three doses of homologous or heterologous vaccine. The results obtained highlight the importance of vaccine boosters in eliciting neutralizing antibody responses against Omicron sub-lineages, and suggest that the adenovirus vectored vaccine elicits a lower response against BA.1 than against BA.2 sub-lineage.