Frontiers in Immunology (Mar 2023)

Pre-existing immunity to SARS-CoV-2 before the COVID-19 pandemic era in Cameroon: A comparative analysis according to HIV-status

  • Abba Aissatou,
  • Abba Aissatou,
  • Joseph Fokam,
  • Joseph Fokam,
  • Joseph Fokam,
  • Joseph Fokam,
  • Ezechiel Ngoufack Jagni Semengue,
  • Ezechiel Ngoufack Jagni Semengue,
  • Ezechiel Ngoufack Jagni Semengue,
  • Désiré Takou,
  • Aude Christelle Ka’e,
  • Aude Christelle Ka’e,
  • Collins Chenwi Ambe,
  • Collins Chenwi Ambe,
  • Alex Durand Nka,
  • Alex Durand Nka,
  • Alex Durand Nka,
  • Sandrine Claire Djupsa,
  • Grâce Beloumou,
  • Laura Ciaffi,
  • Michel Carlos Tommo Tchouaket,
  • Michel Carlos Tommo Tchouaket,
  • Audrey Rachel Mundo Nayang,
  • Willy Leroi Togna Pabo,
  • René Ghislain Essomba,
  • René Ghislain Essomba,
  • René Ghislain Essomba,
  • Edie G. E. Halle,
  • Marie-Claire Okomo,
  • Marie-Claire Okomo,
  • Marie-Claire Okomo,
  • Anne-Cecile ZK. Bissek,
  • Rose Leke,
  • Rose Leke,
  • Yap Boum,
  • Georges Alain Etoundi Mballa,
  • Georges Alain Etoundi Mballa,
  • Carla Montesano,
  • Carlo-Federico Perno,
  • Vittorio Colizzi,
  • Vittorio Colizzi,
  • Vittorio Colizzi,
  • Alexis Ndjolo,
  • Alexis Ndjolo

DOI
https://doi.org/10.3389/fimmu.2023.1155855
Journal volume & issue
Vol. 14

Abstract

Read online

BackgroundThe lower burden of COVID-19 in tropical settings may be due to preexisting cross-immunity, which might vary according to geographical locations and potential exposure to other pathogens. We sought to assess the overall prevalence of SARS-CoV-2 antibodies and determine SARS-CoV-2 seropositivity according to HIV-status before the COVID-19 pandemic era.MethodsA cross-sectional and comparative study was conducted at the Chantal BIYA International Reference Centre (CIRCB) on 288 stored plasma samples (163 HIV-positive versus 125 HIV-negative); all collected in 2017-2018, before the COVID-19 pandemic era. Abbott Panbio™ COVID-19 IgG/IgM assay was used for detecting SARS-CoV-2 immunoglobulin G (IgG) and M (IgM). Among people living with HIV (PLHIV), HIV-1 viral load and TCD4 cell count (LTCD4) were measured using Abbott Real Time PCR and BD FACSCalibur respectively. Statistical analyses were performed, with p<0.05 considered statistically significant.ResultsThe median [IQR] age was 25 [15-38] years. Overall seropositivity to SARS-CoV-2 antibodies was 13.5% (39/288) of which 7.3% (21) was IgG, 7.3% (21) IgM and 1.0% (3) IgG/IgM. According to HIV-status in the study population, SARS-CoV-2 seropositivity was 11.0% (18/163) among HIV-positive versus 16.8% (21/125) among HIV-negative respectively, p=0.21. Specifically, IgG was 6.1% (10/163) versus 8.8% (11/125), p=0.26; IgM was 5.5% (9/163) versus 9.6%, (12/125), p=0.13 and IgG/IgM was 0.6% (1/163) versus 1.6% (2/125) respectively. Among PLHIV, SARS-CoV-2 seropositivity according to CD4 count was 9.2% (≥500 cells/µL) versus 1.8% (200-499 cells/µL), (OR=3.5; p=0.04) and 0.6% (<200 cells/µL), (OR=17.7; p<0.01). According to viral load, SARS-CoV-2 seropositivity was 6.7% (≥40 copies/mL) versus 4.9% (<40 copies/mL), (OR= 3.8; p<0.01).ConclusionBefore COVID-19 in Cameroon, cross-reactive antibodies to SARS-CoV-2 were in circulation, indicating COVID-19 preexisting immunity. This preexisting immunity may contribute in attenuating disease severity in tropical settings like Cameroon. Of relevance, COVID-19 preexisting immunity is lower with HIV-infection, specifically with viral replication and poor CD4-cell count. As poor CD4-count leads to lower cross-reactive antibodies (regardless of viral load), people living with HIV appear more vulnerable to COVID-19 and should be prioritized for vaccination.

Keywords