Seroprevalence of Hepatitis B virus and human immunodeficiency virus co-infection in pregnant women from Osun State, Nigeria.

INTRODUCTION: Hepatitis B virus and human immunodeficiency virus (HBV/HIV) co-infection is a global health concern due to its significant impact on morbidity and mortality. Reports of HBV/HIV co-infections are increasing in Nigeria, but information on the disease burden in pregnant women and its implications on the fetus is scarce. This study aimed to determine the prevalence of HBV/HIV co-infection in pregnant women. In addition, the study identified the risk factors for the disease in pregnant women attending antenatal clinics in Osun State, Nigeria. METHODOLOGY: We collected plasma samples from 303 consenting pregnant women and used enzyme-linked immunosorbent assay (ELISA) to test for HBV (HBsAg) and HIV I/II antigens. We obtained demographic and risk factor data on HBV and HIV transmission using a structured questionnaire. RESULTS: Our analysis revealed a prevalence of 3.96% for HBV/HIV co-infection in pregnant women. Bivariate analysis indicated a history of blood transfusion, oral or anal sex, and multiple sexual partners may be associated with an increased likelihood of HBV/HIV co-infection in pregnant women. After adjusting for other variables in multivariate analysis, none of these risk factors were significant at the 5% level. In contrast, formal education was a potential preventive factor in this population. CONCLUSIONS: Our study provides valuable information on the disease burden of HBV/HIV co-infection in pregnant women in Osun State, Nigeria, highlighting the importance of routine screening for HBV and HIV during antenatal care and emphasizing the importance of implementing preventive measures to reduce the morbidity and mortality associated with HBV/HIV co-infection.

Immunological insights into COVID-19 in Southern Nigeria.

Introduction: One 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. Methods: We 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. Result: Our 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. Discussion: These 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.