einfection by the SARS-CoV-2 Gamma variant in blood donors in Manaus, Brazi

Author(s):Show less -

Prete, Jr., Carlos A. ^[1] ; Buss, Lewis F. ^[2] ; Buccheri, Renata ^[3] ; Abrahim, Claudia M. M. ^[4] ; Salomon, Tassila ^[5] ; Crispim, Myuki A. E. ^[4] ; Oikawa, Marcio K. ^[6] ; Grebe, Eduard ^{[3, 7, 8]} ; da Costa, Allyson G. ^[4] ; Fraiji, Nelson A. ^[4] ; Carvalho, Maria do P. S. S. ^[4] ; Whittaker, Charles ^{[9, 10]} ; Alexander, Neal ^[11] ; Faria, Nuno R. ^{[2, 9, 10, 12]} ; Dye, Christopher ^[12] ; Nascimento, Vitor H. ^[1] ; Busch, Michael P. ^{[3, 7]} ; Sabino, Ester Cerdeira ^[2]

Affiliation:Show less -

^[1] Univ Sao Paulo, Dept Elect Syst Engn, Av Prof Luciano Gualberto, Travessa 3, BR-158 Sao Paulo - Brazil

^[2] Univ Sao Paulo, Fac Med, Inst Med Trop, Dept Molestias Infecciosas & Parasitarias, Av Dr Eneas de Carvalho 470, 1 Andar, BR-05403000 Sao Paulo - Brazil

^[3] Vitalant Res Inst, 270 Masonic Ave, San Francisco, CA - USA

^[4] Fundacao Hosp Hematol & Hemoterapia Amazonas, Av Constantino Nery, BR-4397 Manaus, Amazonas - Brazil

^[5] Fac Ciencias Med Minas Gerais, Alameda Ezequiel Dias, BR-275 Belo Horizonte, MG - Brazil

^[6] Univ Fed ABC, Ctr Math Comp & Cognit, Rua Arcturus 03, Sao Bernardo Do Campo - Brazil

^[7] Univ Calif San Francisco, 1001 Potrero Ave, San Francisco, CA 94143 - USA

^[8] Stellenbosch Univ, SACEMA, 19 Jonkershoek Rd, Stellenbosch - South Africa

^[9] Imperial Coll London, MRC Ctr Global Infect Dis Anal, Sch Publ Hlth, South Kensington Campus, London SW7 2AZ - England

^[10] Imperial Coll London, Abdul Latif Jameel Inst Dis & Emergency Analyt J, Sch Publ Hlth, South Kensington Campus, London SW7 2AZ - England

^[11] London Sch Hyg & Trop Med, Dept Infect Dis Epidemiol, LSHTM, Keppel St, London WC1E 7HT - England

^[12] Univ Oxford, Dept Zool, South Parks Rd, Oxford OX1 3SZ - England

• Document type: Journal article
• Source: BMC INFECTIOUS DISEASES; v. 22, n. 1 FEB 5 2022.
• Web of Science Citations: 0

Abstract

Background The city of Manaus, north Brazil, was stricken by a second epidemic wave of SARS-CoV-2 despite high seroprevalence estimates, coinciding with the emergence of the Gamma (P.1) variant. Reinfections were postulated as a partial explanation for the second surge. However, accurate calculation of reinfection rates is difficult when stringent criteria as two time-separated RT-PCR tests and/or genome sequencing are required. To estimate the proportion of reinfections caused by Gamma during the second wave in Manaus and the protection conferred by previous infection, we identified anti-SARS-CoV-2 antibody boosting in repeat blood donors as a mean to infer reinfection. Methods We tested serial blood samples from unvaccinated repeat blood donors in Manaus for the presence of anti-SARS-CoV-2 IgG antibodies using two assays that display waning in early convalescence, enabling the detection of reinfection-induced boosting. Donors were required to have three or more donations, being at least one during each epidemic wave. We propose a strict serological definition of reinfection (reactivity boosting following waning like a V-shaped curve in both assays or three spaced boostings), probable (two separate boosting events) and possible (reinfection detected by only one assay) reinfections. The serial samples were used to divide donors into six groups defined based on the inferred sequence of infection and reinfection with non-Gamma and Gamma variants. Results From 3655 repeat blood donors, 238 met all inclusion criteria, and 223 had enough residual sample volume to perform both serological assays. We found 13.6% (95% CI 7.0-24.5%) of all presumed Gamma infections that were observed in 2021 were reinfections. If we also include cases of probable or possible reinfections, these percentages increase respectively to 22.7% (95% CI 14.3-34.2%) and 39.3% (95% CI 29.5-50.0%). Previous infection conferred a protection against reinfection of 85.3% (95% CI 71.3-92.7%), decreasing to respectively 72.5% (95% CI 54.7-83.6%) and 39.5% (95% CI 14.1-57.8%) if probable and possible reinfections are included. Conclusions Reinfection by Gamma is common and may play a significant role in epidemics where Gamma is prevalent, highlighting the continued threat variants of concern pose even to settings previously hit by substantial epidemics. (AU)

• 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
• 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