Disparities in anti-SARS-CoV-2 reactivity according to vaccines administered in the era of omicron in Cameroon: Lessons for future outbreak response
- PMID: 40106487
- PMCID: PMC11922206
- DOI: 10.1371/journal.pgph.0004312
Disparities in anti-SARS-CoV-2 reactivity according to vaccines administered in the era of omicron in Cameroon: Lessons for future outbreak response
Abstract
With the advent of COVID-19, anti-SARS-CoV-2 vaccines were a global health priority, but evidence on their significance within tropical settings remained limited. We sought to assess the distribution of anti-SARS-CoV-2 antibodies according to vaccine status and types of vaccines administered in Cameroon during Omicron waves. A community based cross-sectional sero-survey was conducted from February-15 through July-31 2022 among individuals tested for COVID-19 in Yaoundé-Cameroon. Sociodemographic data were collected from participants. Anti-SARS-CoV-2 antibodies (both IgG and IgM) were tested on plasma and statistical analyses were performed wherever appropriate. Logistic regression was done with p<0.05 considered statistically significant. Overall, 2449 participants were enrolled: median-age was 40 [31-49], 56.4% (1382/2449) men, 2.2% (54/2449) with flu-like symptoms and 19.6% (481/2449) reporting previous SARS-CoV-2 positivity. Regarding COVID-19 vaccination, 67.5% (1652/2449) had received at least one dose, 55.0% (909/1652) two-dose series and 37.1% (613/1652) received additional booster doses. Median duration from vaccination to phlebotomy was 5 [4-9] months. Seroprevalence of anti-SARS-CoV-2 antibodies was 81.1% (1987/2449). Following logistic regression, vaccine status (aOR=1.95), booster doses (aOR=1.36), post-vaccination time (≤5 months; aOR=1.64), Pfizer (aOR=2.07) and Moderna (aOR=1.52) vaccines, were all associated with a high prevalence of anti-SARS-CoV-2 antibodies (all p<0.05). This high seroprevalence of anti-SARS-CoV-2 antibodies suggests a certain degree of immunity/protection at community-level in Cameroon during Omicron waves, with Pfizer and Moderna inducing greater immunogenicity. However, rapid antibody waning (~5 months) calls for vaccine updates with novel variants (arising from a rapidly evolving virus) that could compromise already acquired immunity.
Copyright: © 2025 Ngoufack Jagni Semengue et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Conflict of interest statement
The authors declare no existing conflicts of interest. The funders had no role in the design of the study; in the collection, analyses, or interpretation of data; in the writing of the manuscript; or in the decision to publish the results.
References
-
- World Health Organization (WHO). Origin of SARS-CoV-2. 2020. [cited 29 Dec 2022]. Available from: https://www.who.int/publications/i/item/origin-of-sars-cov-2
-
- Nations Unies Cameroun. Plan de réponses socio-économiques des NU contre la Covid-19. [cited 25 Aug 2023]. Available from: https://unsdg.un.org/sites/default/files/2020-07/CMR_Socioeconomic-Respo...
-
- COVID-19: Cameroon adopts 3T strategy but emergency fund remains cloudy - Good Governance Africa. [cited 25 Aug 2023]. Available from: https://gga.org/covid-19-cameroon-adopts-3t-strategy-but-emergency-fund-...
Grants and funding
LinkOut - more resources
Full Text Sources
Miscellaneous