ABSTRACT
Background: SARS-CoV-2 seroprevalence data in women living with HIV (WLHIV), their infants and associated risk factors in this subpopulation remain limited. We retrospectively measured SARS-CoV-2 seroprevalence from 09/2019- 12/2021 among WLHIV and their children in the PROMOTE observational cohort in Uganda, Malawi, and Zimbabwe prior to widespread SARS-CoV-2 vaccination in those countries. Method(s): Sociodemographic, clinical data and blood were collected q6 months. Plasma stored during 3 waves of the COVID-19 pandemic in East/ Southern Africa were tested for SARS-CoV-2 specific IgG antibodies (Ab) using serological assays that detect adaptive immune responses to SARS-CoV-2 spike protein. Modified-Poisson regression models were used to calculate prevalence rate ratios (PRR) and 95% confidence intervals (CI) to identify sociodemographic and clinical risk factors. Result(s): Plasma samples from 979 PROMOTE mothers and 1332 children were analysed. We found no significant differences in baseline characteristics between participants testing positive (+) and negative (-) for SARS-CoV-2 Ab. Overall maternal SARS-CoV-2 seroprevalence was 57.6% (95%CI: 54.5-60.7) and 39.3% (95%CI: 36.7-41.9) for infants. The earliest + result was detected from a sample collected on 09/2019, in Malawi. Factors significantly associated with SARS-CoV-2 seropositivity were country of origin (reference Uganda, aPRR 1.45, 95%CI: 1.24-1.69) and non-breastfeeding mother (aPRR=1.22, 95%CI: 1.02-1.48). Children above 5 years had a 10% increased risk of SARS-CoV-2 seropositivity (aPRR=1.10, 95%CI: 0.90-1.34) when compared to younger children. We found no statistically significant association with sanitation, household density, distance to clinic, maternal employment, ART regimen or viral load. Mother/infant SARS-CoV-2 serostatuses were discordant in 373/865 (43.1%) families tested: mothers+/children- in 51.2%;mothers-/children+ in 12%;child+/sibling+ concordance was 21.4%. Conclusion(s): These SARS-CoV-2 seroprevalence data indicate that by late 2021, about half of mothers and about a third of children in a cohort of HIV-affected families in eastern/southern Africa had been infected with SARS-CoV-2. Breastfeeding was protective for mothers, likely because of the need to stay home for young children. Discordant results between children within same families underscores the need to further understand transmission dynamics within households.
ABSTRACT
Background: Given the paucity of data on safety and effectiveness of mRNA COVID-19 booster vaccinations in lower income settings with high HIV prevalence, we evaluated a heterologous mRNA-1273 (Moderna) boost after priming with 1 or 2 doses of Ad26.COV2.S (Janssen, Johnson & Johnson) vaccine among health care workers (HCWs) in South Africa. Method(s): SHERPA is an open-label, phase 3 mRNA-1273 booster study, nested in the Sisonke Phase 3b implementation trial, that vaccinated ~500000 HCWs with 1 or 2 doses of Ad26.COV2.S from Feb and Dec 2021. Sisonke participants were offered mRNA-1273 boosters between 23 May and 12 Nov 2022 (median 17 and 8 months after 1 and 2 Ad26.COV2.S, respectively), with data cut-off on 12 Dec 2022. Reactogenicity and adverse events (AEs) were self-reported via an online data entry link shared by SMS with participants 1, 7 and 28 days after boosting. Using national databases analyses are underway to compare effectiveness against COVID-19 infections and severe disease with Sisonke participants who did not receive the booster. Result(s): 12188 HCWs (79.5% female, 28.6% with self-reported previous COVID-19 diagnosis) received a mRNA-1273 booster, of whom 44.6% and 55.4% had received 1 and 2 prior Ad26.COV2.S vaccines in Sisonke, respectively. 3056 (25.2%) reported being HIV positive, more among those receiving only 1 previous Ad26.COV2.S (26.8% vs 23.9%), and 1.4% reported not being on antiretroviral therapy. 17.0% of participants reported hypertension and 6.4% diabetes mellitus. 262 participants (2.1% of women, 2.5% of men) reported 234 reactogenicity events and 95 AEs post-vaccination, with more reported by those with prior COVID-19 infection (3.5% vs 1.6%), HIV negative status (2.5% vs 1.2%) and those who received 2 prior doses of Ad26.COV2.S (2.4% vs 1.8%) (Table). Among 159 (1.3%) reporting injection site reactions the commonest were pain (59.7%), swelling (42.1%) and induration (20.1%). Of 177 (1.5%) systemic reactogenicity events (all grade 1 or 2 severity), the commonest were myalgia (69.5%), headache (67.8%) and fever (37.9%). 14 participants had AEs of special interest or serious AEs, of which 4 (all AESIs of ageusia or anosmia) were deemed related to the booster. 13 COVID-19 infections occurred a median of 125 days post booster vaccination (IQR 90-154) after 3477 person-years of follow up. Conclusion(s): A mRNA-1273 booster administered after 1 or 2 doses of Ad26. COV2.S was well tolerated regardless of HIV status, other chronic conditions or prior COVID-19 infection.
ABSTRACT
Background: The Sisonke Phase IIIB open-label implementation study vaccinated health care workers (HCWs) with the single dose Ad26.COV2.S vaccine during two phases of the South African Covid-19 epidemic, dominated first by the Beta followed by the Delta variant of concern. Methods: HCWs were vaccinated over 3 months (17 February-17 May 2021). Safety was monitored by self-reporting, facility reporting and linkage to national databases. Vaccine effectiveness (VE) against Covid-19 related hospitalisation, hospitalisation requiring critical or intensive care and death, ascertained 28 days or more post vaccination was assessed up until 17 July 2021. Nested sub-cohorts (A and B) from two national medical schemes were evaluated to assess VE using a matched retrospective cohort design. Results: Over the 3-month period, 477234 HCWs were vaccinated in 122 vaccination sites across South Africa. VE derived from the sub-cohorts comprising 215 813 HCWs was 83% (95% CI 75-89) to prevent Covid-19 deaths, 75% (95% CI 69-82) to prevent hospital admissions requiring critical or intensive care and 67% (95% CI 62-71) to prevent Covid-19 related hospitalisations. The VE was maintained in older HCWs and those with comorbidities including HIV infection. VE remained consistent throughout the Beta and Delta dominant phases of the study. 10279 adverse events were reported and 139 (1.4%) were serious, including two cases of thrombosis with thrombocytopenia syndrome and four cases of Guillain-Barré syndrome who recovered. Conclusion: The single dose Ad26.COV2.S was safe and effective against severe Covid-19 disease and death post-vaccination, and against both Beta and Delta variants providing real-world evidence for its use globally.