Abstract Body


Adults living with HIV may have higher risk of SARS-CoV-2 infection than HIV negative adults. There are no published data on seroprevalence of SARS-CoV-2 in children and adolescents living with HIV (CALWHIV).


We did a repeat SARS-CoV-2 seroprevalence study in 7 paediatric HIV observational cohorts in 5 countries in the European Pregnancy & Paediatric Infections Cohort Collaboration (EPPICC; Belgium, Greece, Spain, Ukraine, United Kingdom (UK)) and also the Cape Town Adolescent Antiretroviral Cohort (CTAAC), South Africa (SA) (CALWHIV and HIV negative adolescents). Participants gave 2 blood samples for SARS-CoV-2 antibody testing ~6 months apart during routine visits between May 2020 and July 2022, and completed questionnaires on SARS-CoV-2 exposure/infection and vaccine status. Clinical and demographic data were extracted from clinic records.


Of 906 participants, 53%(477) were female, 89%(803) CALWHIV, median [IQR] age at first visit 17[15-19] years. Most were enrolled in SA (45%, 410/906), UK (23%, 205/906) or Ukraine (18%, 160/906). 85%(767/906) had 2 blood samples and the rest a single sample. For CALWHIV, at time of first sample, 99%(761/765) were on antiretroviral therapy, median CD4 count was 666[478-858] cells/mL, 70%(535/764) had HIV-1 viral load < 50c/mL. Of those with known SARS-CoV-2 vaccine status, 23%(181/773) CALWHIV and 22% (22/100) HIV negative participants received ≥1 vaccine dose. 6%(43/762) of CALWHIV had a documented prior SARS-CoV-2 positive PCR (including 2 hospitalised for COVID, neither severe), and 16%(124/762) self-reported previous positive test and/or COVID-19 symptoms, giving a total of 17%(128/762) with any previous infection. Based on serum testing, 63%(562/898) of participants overall were seropositive on at least one sample (55% (269/488) Europe, 67% (205/307) SA CALWHIV, 85% (88/103) SA HIV negative group), and among the unvaccinated subgroup, 53%(408/765) were seropositive (41% (167/412) Europe, 64% (168/263) SA CALWHIV, 81% (73/90) SA HIV negative). Among samples taken prior to or in absence of vaccination, the proportion testing antibody positive increased over time (Figure). Of unvaccinated CALWHIV with ≥1 positive result, 17%(52/299) reported any previous SARS-CoV-2 infection.


Most CALWHIV were SARS-CoV-2 seropositive by mid-2022 despite low vaccine coverage. Fewer had documented or self-reported COVID-19 infection or disease, suggesting most infections were mild or asymptomatic.

Seroprevalence of SARS-CoV-2 antibodies in Europe and South Africa, by HIV status and calendar quarter of sampling. Colours indicate dominant variant based on GISAID data for adults and children.