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ORIGINAL RESEARCH article

Front. Public Health
Sec. Infectious Diseases: Epidemiology and Prevention
Volume 13 - 2025 | doi: 10.3389/fpubh.2025.1522733

Pre-pandemic cross-reactive antibody and cellular responses against SARS-CoV-2 among female sex workers in Dakar, Senegal

Provisionally accepted
Bobby Brooke Herrera Bobby Brooke Herrera 1,2Beth Chaplin Beth Chaplin 1Souleymane MBOUP Souleymane MBOUP 3Adam Abdullahi Adam Abdullahi 4Michelle He Michelle He 1Sydney M Fisher Sydney M Fisher 1Alani Sulaimon Akanmu Alani Sulaimon Akanmu 5Charlotte A Chang Charlotte A Chang 1Donald J Hamel Donald J Hamel 1Ravindra K Gupta Ravindra K Gupta 4Phyllis Kanki Phyllis Kanki 1*
  • 1 Department of Immunology and Infectious Diseases, School of Public Health, Harvard University, Boston, United States
  • 2 Department of Medicine, School of Medicine, Rutgers, The State University of New Jersey, New Brunswick, United States
  • 3 Institut de Recherche en Santé, de Surveillance Epidemiologique et de Formations, Dakar, Senegal
  • 4 Cambridge Institute for Therapeutic Immunology and Infectious Disease, School of Clinical Medicine, University of Cambridge, Cambridge, England, United Kingdom
  • 5 College of Medicine, University of Lagos, Lagos, Nigeria

The final, formatted version of the article will be published soon.

    The COVID-19 pandemic had a severe impact globally, yet African populations exhibited unexpectedly lower rates of severe disease and mortality. We investigated the potential role of pre-existing immunity in shaping the epidemiology of COVID-19 in Africa.Methods: Plasma collected from Senegalese female sex workers prior to the COVID-19 pandemic was screened for SARS-CoV-2 and human coronavirus (hCoV) antibodies by virion immunoblots. For antibody-reactive plasma, paired peripheral blood mononuclear cells were stimulated by fusion proteins and IFN-γ cellular responses were assessed via ELISPOT.We observed substantial levels of pre-existing cross-reactive immunity to SARS-CoV-2, stemming from prior exposure to seasonal hCoVs. Our antibody analysis revealed a 23.5% (47/200) seroprevalence rate against SARS-CoV-2 nucleocapsid (N). These samples were then probed for antibodies against hCoV spike (S) and/or N antigens;-85.1% (40/47), 70.2% (33/47), and 95.7% (45/47) were antibody reactive against hCoV-229E, hCoV-OC43, or hCoV-HKU1 , respectively. Our analysis of cellular responses also demonstrated cross-reactivity to SARS-CoV-2 with 80.0% (36/45) and 82.2% (37/45) showing IFN-γ responses against S and N, respectively. A unique prepandemic subject had cross-reactive SARS-CoV-2 S antibodies with detectable neutralization and cross-reactive cellular responses.Conclusions: These findings suggest that prior hCoV exposure may induce cross-reactive adaptive immunity, potentially contributing to protection against COVID-19. Our study provides unique data on the dynamics of hCoV and SARS-CoV-2 immunity in Senegal and underscores the importance of understanding the role of pre-existing immunity in shaping COVID-19 outcomes globally.

    Keywords: SARS-CoV-2, antibody, cellular responses, cross-reactivity, Senegal

    Received: 26 Nov 2024; Accepted: 06 Jan 2025.

    Copyright: © 2025 Herrera, Chaplin, MBOUP, Abdullahi, He, Fisher, Akanmu, Chang, Hamel, Gupta and Kanki. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.

    * Correspondence: Phyllis Kanki, Department of Immunology and Infectious Diseases, School of Public Health, Harvard University, Boston, United States

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