Persistence of anti-SARS-CoV-2 antibodies and immune memory in Nigerian volunteers: A comparative study of partial and complete vaccination

Document Type : Original Article

Authors

1 Medical Laboratory Science Department, Edo State University, Uzairue, Edo State, Nigeria

2 Medical Laboratory Science Department, Nigerian Navy Hospital, Warri, Delta State, Nigeria

Abstract

Background: Understanding vaccine-induced immunity in diverse populations is critical for effective public health strategies. This study aimed to evaluate the persistence of anti-SARS-CoV-2 antibodies and immune memory in Nigerian volunteers who received partial and complete COVID-19 vaccination schedules. Methods: A cross-sectional study was conducted with 270 participants from three tertiary healthcare centers in Southwest Nigeria. Participants were grouped based on their vaccination status: single dose, double dose, or complete vaccination. Blood samples were collected and analyzed using ELISA to quantify levels of SARS-CoV-2 immunoglobulin G (IgG), immunoglobulin A (IgA), and immunoglobulin M (IgM). Results: A trend of increasing immunoglobulin levels was observed across groups, with IgM showing the most pronounced increase. However, the differences were not statistically significant (p > 0.05). Detectable antibody levels were present in all groups, indicating immune protection even in partially vaccinated individuals. Conclusion: This study highlights the persistence of antibody responses following COVID-19 vaccination in Nigeria, with implications for vaccination policies and booster dose recommendations. While partial vaccination provides some immune protection, further research with larger cohorts and longer follow-ups is essential to fully understand the dynamics of vaccine-induced immunity in diverse populations.

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