1 Department of Preventive and Social Medicine, School of Medicine, Universidade Federal da Bahia, Salvador, Brazil;
| 2 Center for Vector-borne Infectious Diseases, Department of Microbiology, Immunology & Pathology, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins, Colorado;
| 3 Department of Virology, Instituto Aggeu Magalhães, Fundação Oswaldo Cruz, Recife, Brazil;
| 4 Infectious Disease and Microbiology Department, University of Pittsburgh, Pittsburgh, Pennsylvania;
| 5 Faculty of Medical Science, Universidade de Pernambuco, Recife, Brazil (Castanha, P.) ;
| 6 Department of Parasitology, Instituto Aggeu Magalhães, Fundação Oswaldo Cruz, Recife, Brazil;
| 7 Center for Global Health, Colorado School of Public Health, Aurora, Colorado;
| 8 Department of Epidemiology, Colorado School of Public Health, Aurora, Colorado
It is currently not clear whether humoral immunity to Zika virus (ZIKV) elicited upon natural ZIKV infection is long-lasting. In addition, cross-reactivity of anti-ZIKV antibodies with antigenically related dengue viruses (DENV) may have biological implications in nonnaive individuals who subsequently acquire a heterotypic infection. Cross-reactive humoral immunity between ZIKV and DENV also complicates the interpretation of serological tests to evaluate previous exposure to either virus. Here, we have measured the 2-year decay of ZIKV neutralizing antibodies in people living in a ZIKV/DENV endemic area in Brazil who were identified as having an acute (group 1) or past (but recent) infection (group 2) with ZIKV in 2015–2016. The titers of neutralizing antibodies to ZIKV decreased 9.1 and 2.3 times in groups 1 and 2, respectively. We also show that the plaque reduction neutralization assay (PRNT) is a reliable method to measure past exposure to ZIKV in coendemic areas.
Address correspondence to Tereza Magalhaes, Largo Terreiro de Jesus s/n, Pelourinho, Salvador-BA, 40026-010, Brazil. E-mails: firstname.lastname@example.org
Financial support: This research was funded by a National Institutes of Health/National Institute of Allergy and Infectious Diseases grant (R21129464), the European Union’s Horizon 2020 Research and Innovation Program (ZIKAlliance Grant Agreement No. 734548), and the European Union’s 7th Framework Programme (IDAMS Grant Agreement No. 281803). The 2015–2016 and 2017 study protocols were approved by the Instituto Aggeu Magalhães (no. 28309414.9.0000.5190 and no. 63441516.6.0000.5190) and Colorado State University (no. 16-6579HH) Institutional Review Boards.
Authors’ addresses: Tereza Magalhaes, Universidade Federal da Bahia, Preventive and Social Medicine, Salvador, Brazil, and Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, CO, E-mail: email@example.com. Clarice N. L. Morais, Elisa A. N. Azevedo, Iracema J. A. A. Jacques, and Marli T. Cordeiro, Instituto Aggeu Magalhães, Virology, Recife, Brazil, E-mails: firstname.lastname@example.org. email@example.com, firstname.lastname@example.org, and email@example.com. Priscila M. S. Castanha, Infectious Disease and Microbiology, University of Pittsburgh, Pittsburgh, PA, and Faculty of Medical Science, Universidade de Pernambuco, Recife, Brazil, E-mail: firstname.lastname@example.org. Cynthia Braga, Parasitology, Instituto Aggeu Magalhães, Recife, Brazil, E-mail: email@example.com. Thomas Jaenisch, Colorado School of Public Health, Center for Global Health, Aurora, CO, and Colorado School of Public Health, Epidemiology, Aurora, CO, E-mail: firstname.lastname@example.org. Ernesto T. A. Marques, Infectious Disease and Microbiology, University of Pittsburgh, Pittsburgh, PA, E-mail: email@example.com. Brian D. Foy, Microbiology, Immunology & Pathology, Colorado State University, Ft. Collins, CO, E-mail: firstname.lastname@example.org.