TITLE:
Evolution of Anti-SARS-CoV-2 Humoral Immunity Following COVID-19 Infection among Vaccinated and Previously Infected Healthcare Workers in Côte d’Ivoire
AUTHORS:
Yéboah Oppong Richard, Goran-Kouacou Amah Patricia Victorine, Adou Adjoumanvoule Honoré, Assi Aya Ursule Aniela, Mémel Lasme Roselle Charline, Séri Yida Jocelyne, Koya Herbert Gautier, Moussa Salimata, Oura Brou Doris, Angbonon Tychique Elysée Attoukoula, N’Guéssan Koffi, Siransy Kouabla Liliane, Dassé Séry Romuald
KEYWORDS:
Neutralizing Antibodies, COVID-19, IgG, Healthcare Workers, SARS-CoV-2
JOURNAL NAME:
Open Journal of Immunology,
Vol.15 No.4,
December
24,
2025
ABSTRACT: Background: Coronavirus disease (or COVID-19), caused by the novel coronavirus SARS-CoV-2, the most virulent identified to date, remains a major global public health challenge. Given the essential role of specific anti-SARS-CoV-2 humoral immunity in protection against reinfection, it is crucial to characterize its kinetics to adapt vaccination strategies. This longitudinal study aimed to evaluate the kinetics of anti-SARS-CoV-2 IgG and neutralizing antibodies produced by previously immunized subjects in response to new infection over 28 days within a cohort of 36 healthcare workers diagnosed with COVID-19 in Côte d’Ivoire. Methods: Between April and June 2022, healthcare professionals infected with COVID-19 were recruited from three university hospitals in Abidjan. Serum samples were collected, and anti-Spike IgG and neutralizing antibodies were quantified using a competitive enzyme immunoassay (Chorus TRIO, DIESSE). Both antibody types were evaluated at days 0, 7, 14, 21, and 28 following diagnosis. Results: IgG levels increased significantly over time (p Conclusion: IgG levels gradually increased, while neutralizing antibody titres declined after peaking on day 14.