Frontiers in Immunology (Jan 2024)

Immunological insights into COVID-19 in Southern Nigeria

  • Chinedu A. Ugwu,
  • Chinedu A. Ugwu,
  • Oluwasina Alao,
  • Oluwasina Alao,
  • Oluwagboadurami G. John,
  • Oluwagboadurami G. John,
  • Blossom Akinnawo,
  • Blossom Akinnawo,
  • Israel Ajayi,
  • Israel Ajayi,
  • Ooreofe Odebode,
  • Ooreofe Odebode,
  • Ifeoluwa Bejide,
  • Allan Campbell,
  • Allan Campbell,
  • Julian Campbell,
  • Julian Campbell,
  • Jolly A. Adole,
  • Jolly A. Adole,
  • Idowu B. Olawoye,
  • Idowu B. Olawoye,
  • Kazeem Akano,
  • Kazeem Akano,
  • Johnson Okolie,
  • Philomena Eromon,
  • Peter Olaitan,
  • Ajibola Olagunoye,
  • Ibukun Adebayo,
  • Victor Adebayo,
  • Elizabeth Babalola,
  • Omowumi Abioye,
  • Nnennaya Ajayi,
  • Emeka Ogah,
  • Kingsley Ukwaja,
  • Sylvanus Okoro,
  • Ogbonnaya Oje,
  • Ojide Chiedozie Kingsley,
  • Matthew Eke,
  • Venatius Onyia,
  • Olivia Achonduh-Atijegbe,
  • Friday Elechi Ewah,
  • Mary Obasi,
  • Violet Igwe,
  • Olufemi Ayodeji,
  • Abejegah Chukwuyem,
  • Sampson Owhin,
  • Nicholas Oyejide,
  • Sylvester Abah,
  • Winifred Ingbian,
  • Moyosoore Osoba,
  • Ahmed Alebiosu,
  • Angalee Nadesalingam,
  • Ernest T. Aguinam,
  • George Carnell,
  • Nina Krause,
  • Andrew Chan,
  • Charlotte George,
  • Rebecca Kinsley,
  • Paul Tonks,
  • Nigel Temperton,
  • Jonathan Heeney,
  • Christian Happi,
  • Christian Happi

DOI
https://doi.org/10.3389/fimmu.2024.1305586
Journal volume & issue
Vol. 15

Abstract

Read online

IntroductionOne of the unexpected outcomes of the COVID-19 pandemic was the relatively low levels of morbidity and mortality in Africa compared to the rest of the world. Nigeria, Africa's most populous nation, accounted for less than 0.01% of the global COVID-19 fatalities. The factors responsible for Nigeria's relatively low loss of life due to COVID-19 are unknown. Also, the correlates of protective immunity to SARS-CoV-2 and the impact of pre-existing immunity on the outcome of the COVID-19 pandemic in Africa are yet to be elucidated. Here, we evaluated the natural and vaccine-induced immune responses from vaccinated, non-vaccinated and convalescent individuals in Southern Nigeria throughout the three waves of the COVID-19 pandemic in Nigeria. We also examined the pre-existing immune responses to SARS-CoV-2 from samples collected prior to the COVID-19 pandemic.MethodsWe used spike RBD and N- IgG antibody ELISA to measure binding antibody responses, SARS-CoV-2 pseudotype assay protocol expressing the spike protein of different variants (D614G, Delta, Beta, Omicron BA1) to measure neutralizing antibody responses and nucleoprotein (N) and spike (S1, S2) direct ex vivo interferon gamma (IFNγ) T cell ELISpot to measure T cell responses. ResultOur study demonstrated a similar magnitude of both binding (N-IgG (74% and 62%), S-RBD IgG (70% and 53%) and neutralizing (D614G (49% and 29%), Delta (56% and 47%), Beta (48% and 24%), Omicron BA1 (41% and 21%)) antibody responses from symptomatic and asymptomatic survivors in Nigeria. A similar magnitude was also seen among vaccinated participants. Interestingly, we revealed the presence of preexisting binding antibodies (N-IgG (60%) and S-RBD IgG (44%)) but no neutralizing antibodies from samples collected prior to the pandemic. DiscussionThese findings revealed that both vaccinated, non-vaccinated and convalescent individuals in Southern Nigeria make similar magnitude of both binding and cross-reactive neutralizing antibody responses. It supported the presence of preexisting binding antibody responses among some Nigerians prior to the COVID-19 pandemic. Lastly, hybrid immunity and heterologous vaccine boosting induced the strongest binding and broadly neutralizing antibody responses compared to vaccine or infection-acquired immunity alone.

Keywords