Anti-spike protein antibody titer at the time of breakthrough infection of SARS-CoV-2 omicron

• Published in: Journal of infection and chemotherapy : official journal of the Japan Society of Chemotherapy Vol. 28; no. 7; pp. 1015 - 1017
• Main Authors: Adachi, Eisuke, Nagai, Etsuko, Saito, Makoto, Isobe, Masamichi, Konuma, Takaaki, Koga, Michiko, Tsutsumi, Takeya, Nannya, Yasuhito, Yotsuyanagi, Hiroshi
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier Ltd 01.07.2022; Japanese Society of Chemotherapy and The Japanese Association for Infectious Diseases. Published by Elsevier Ltd
• Subjects: Anti-spike protein antibody; Antibodies, Viral; BNT162 Vaccine; BNT162b2; Breakthrough infection; COVID-19; COVID-19 Vaccines; Humans; mRNA Vaccines; mRNA-1273; Omicron variant; RNA, Viral; SARS-CoV-2; Vaccines, Synthetic; Omicron variant; Anti-spike protein antibody; BNT162b2; Breakthrough infection; mRNA-1273
• ISSN: 1341-321X; 1437-7780; 1437-7780
• DOI: 10.1016/j.jiac.2022.03.021

By December 2021, about 80% of people over the age of 12 had been vaccinated in Japan, and almost all people were vaccinated with the mRNA vaccine. We investigated here the anti-spike protein antibody titer at the time of breakthrough infection of SARS-CoV-2 omicron. A total of 32 SARS-CoV2 omicron breakthrough infection was included in the study. The median antibody titer at breakthrough infection was 776 AU/mL overall, of which the median antibody titer of BNT162b2 vaccinated was 633 AU/mL and that of mRNA-1273 vaccinated was 9416 AU/mL. This result suggests that low levels of antibody titers 6 months after vaccination do not provide sufficient antibodies to prevent the omicron variant breakthrough infection, which may occur with a higher anti-spike antibody titer after vaccination with mRNA-1273. However, antibody titers in some patients were comparable to those immediately after the second vaccination with either mRNA vaccine.