COVID-19 vaccine uptake and effectiveness by time since vaccination in the Western Cape province, South Africa: An observational cohort study during 2020-2022

Background

There are few data on the real-world effectiveness of COVID-19 vaccines and boosting in Africa, which experienced high levels of SARS-CoV-2 infection in a mostly vaccine-naïve population, and has limited vaccine coverage and competing health service priorities. We assessed the association between vaccination and severe COVID-19 in the Western Cape, South Africa.

Methods

We performed an observational cohort study of >2 million adults during 2020-2022. We described SARS-CoV-2 testing, COVID-19 outcomes, and vaccine uptake over time. We used multivariable cox models to estimate the association of BNT162b2 and Ad26.COV2.S vaccination with COVID-19-related hospitalisation and death, adjusting for demographic characteristics, underlying health conditions, socioeconomic status proxies and healthcare utilisation.

Results

By end 2022, only 41% of surviving adults had completed vaccination and 8% a booster dose, despite several waves of severe COVID-19. Recent vaccination was associated with notable reductions in severe COVID-19 during distinct analysis periods dominated by Delta, Omicron BA.1/2 and BA.4/5 (sub)lineages: within 6 months of completing vaccination or boosting, vaccine effectiveness was 46-92% for death (range across periods), 45-92% for admission with severe disease or death, and 25-90% for any admission or death. During the Omicron BA.4/5 wave, within 3 months of vaccination or boosting, BNT162b2 and Ad26.COV2.S were each 84% effective against death (95% CIs: 57-94 and 49-95, respectively). However, there were distinct reductions of VE at larger times post completing or boosting vaccination.

Conclusions

Continued emphasis on regular COVID-19 vaccination including boosting is important for those at high risk of severe COVID-19 even in settings with widespread infection-induced immunity.

Food-based dietary guidelines and nutrition interventions for children at primary healthcare facilities in South Africa

Existing dietary recommendations and nutrition counselling provided to mothers/caregivers at primary healthcare (PHC) facilities are reviewed and analysed to be consistent with food-based dietary guidelines (FBDGs) that are being developed for preschool children. Recommendations provided by the Integrated Management of Childhood Illness and the provincial Paediatric Case Management Guidelines, which are currently implemented at PHC facilities were reviewed. For FBDGs to be consistent with nutrition counselling that is provided to mothers/caregivers at these facilities, various principles need to be promoted. These include among others, exclusive and on-demand breastfeeding in the HIV-negative mother; exclusive breastfeeding with abrupt cessation preferably at 6 months or exclusive, safe and adequate formula feeding in the HIV-infected mother; the introduction of complementary feeds in all infants at 6 months; the provision of energy-dense and micronutrient-enriched (particularly, iron, zinc, calcium and vitamin A) complementary feeds; frequent visits to the healthcare facility; and physical activity aimed at encouraging a healthy lifestyle and preventing overweight and obesity in childhood. The FBDGs should be incorporated into nutrition and child health programmes and be reviewed and modified regularly.