RESUMEN
BACKGROUND: Serological data on endemic human coronaviruses (HCoVs) and SARS-CoV-2 in southern Africa are scarce. Here, we report on i) endemic HCoV seasonality, ii) SARS-CoV-2 seroprevalence, and iii) predictive factors for SARS-CoV-2 seropositivity and strength of SARS-CoV-2 and HCoV serological response during a 17-month period at the start of the COVID-19 pandemic among adults living with HIV. METHODS: Plasma samples were collected from February 2020 to July 2021 within an outpatient HIV cohort in Lesotho. We used the ABCORA multiplex immunoassay to measure antibody responses to endemic HCoV (OC43, HKU1, NL63, and 229E) and SARS-CoV-2 antigens. RESULTS: Results of 3'173 samples from 1'403 adults were included. Serological responses against endemic HCoVs increased over time and peaked in winter/spring. SARS-CoV-2 seropositivity reached >35% among samples collected in early 2021 and was associated with female sex (p = 0.004), obesity (p < 0.001), working outside the home (p = 0.02), and recent tiredness (p = 0.005) or fever (p = 0.007). Positive correlations were observed between the strength of response to endemic HCoVs and to SARS-CoV-2, and between older age or obesity and the IgG response to SARS-CoV-2. CONCLUSIONS: These results add to our understanding of the impact of biological, clinical, and social/behavioural factors on serological responses to coronaviruses in southern Africa.