Predicting SARS-CoV-2 Variant Spread in a Completely Seropositive Population Using Semi-Quantitative Antibody Measurements in Blood Donors

Author(s):Show less -

Buss, Lewis ; Prete, Carlos A. ; Whittaker, Charles ; Salomon, Tassila ; Oikawa, Marcio K. ; Pereira, Rafael H. M. ; Moura, Isabel C. G. ; Delerino, Lucas ; Franca, Rafael F. O. ; Miyajima, Fabio ; Mendrone Jr, Alfredo ; Almeida-Neto, Cesar ; Salles, Nanci A. ; Ferreira, Suzete C. ; Fladzinski, Karine A. ; de Souza, Luana M. ; Schier, Luciane K. ; Inoue, Patricia M. ; Xabregas, Lilyane A. ; Crispim, Myuki A. E. ; Fraiji, Nelson ; Carlos, Luciana M. B. ; Pessoa, Veridiana ; Ribeiro, Maisa A. ; de Souza, Rosenvaldo E. ; Cavalcante, Anna F. ; Valenca, Maria I. B. ; da Silva, Maria, V ; Lopes, Esther ; Filho, Luiz A. ; Mateos, Sheila O. G. ; Nunes, Gabrielle T. ; Schlesinger, David ; Nunes da Silva, Sonia Mara ; Silva-Junior, Alexander L. ; Castro, Marcia C. ; Nascimento, Vitor H. ; Dye, Christopher ; Busch, Michael P. ; Faria, Nuno R. ; Sabino, Ester C.

• Document type: Journal article
• Source: VACCINES; v. 10, n. 9, p. 11-pg., 2022-09-01.

Abstract

SARS-CoV-2 serologic surveys estimate the proportion of the population with antibodies against historical variants, which nears 100% in many settings. New approaches are required to fully exploit serosurvey data. Using a SARS-CoV-2 anti-Spike (S) protein chemiluminescent microparticle assay, we attained a semi-quantitative measurement of population IgG titers in serial cross-sectional monthly samples of blood donations across seven Brazilian state capitals (March 2021-November 2021). Using an ecological analysis, we assessed the contributions of prior attack rate and vaccination to antibody titer. We compared anti-S titer across the seven cities during the growth phase of the Delta variant and used this to predict the resulting age-standardized incidence of severe COVID-19 cases. We tested similar to 780 samples per month, per location. Seroprevalence rose to >95% across all seven capitals by November 2021. Driven by vaccination, mean antibody titer increased 16-fold over the study, with the greatest increases occurring in cities with the highest prior attack rates. Mean anti-S IgG was strongly correlated (adjusted R2 = 0.89) with the number of severe cases caused by Delta. Semi-quantitative anti-S antibody titers are informative about prior exposure and vaccination coverage and may also indicate the potential impact of future SARS-CoV-2 variants. (AU)

• FAPESP's process: 18/14389-0 - Brazil-UK Centre for Arbovirus Discovery, Diagnosis, Genomics and Epidemiology (CADDE)
• Grantee: Ester Cerdeira Sabino
• Support Opportunities: Research Projects - Thematic Grants
• FAPESP's process: 19/21858-0 - Bayesian models for estimating the attack rate of epidemics
• Grantee: Carlos Augusto Prete Junior
• Support Opportunities: Scholarships in Brazil - Doctorate