RESUMEN
OBJECTIVES: We aimed to compare COVID-19 outcomes in the Omicron-driven fourth wave with prior waves in the Western Cape, the contribution of undiagnosed prior infection to differences in outcomes in a context of high seroprevalence due to prior infection, and whether protection against severe disease conferred by prior infection and/or vaccination was maintained. METHODS: In this cohort study, we included public sector patients aged ≥20 years with a laboratory confirmed COVID-19 diagnosis between 14 November-11 December 2021 (wave four) and equivalent prior wave periods. We compared the risk between waves of the following outcomes using Cox regression: death, severe hospitalization or death and any hospitalization or death (all ≤14 days after diagnosis) adjusted for age, sex, comorbidities, geography, vaccination and prior infection. RESULTS: We included 5,144 patients from wave four and 11,609 from prior waves. Risk of all outcomes was lower in wave four compared to the Delta-driven wave three (adjusted Hazard Ratio (aHR) [95% confidence interval (CI)] for death 0.27 [0.19; 0.38]. Risk reduction was lower when adjusting for vaccination and prior diagnosed infection (aHR:0.41, 95% CI: 0.29; 0.59) and reduced further when accounting for unascertained prior infections (aHR: 0.72). Vaccine protection was maintained in wave four (aHR for outcome of death: 0.24; 95% CI: 0.10; 0.58). CONCLUSIONS: In the Omicron-driven wave, severe COVID-19 outcomes were reduced mostly due to protection conferred by prior infection and/or vaccination, but intrinsically reduced virulence may account for an approximately 25% reduced risk of severe hospitalization or death compared to Delta.
RESUMEN
The Western Cape province was the early epicentre of the coronavirus disease 2019 pandemic in South Africa and on the African continent. In this short article we report on an initiative set up within the provincial Department of Health early in the pandemic to facilitate collective learning and support for health workers and managers across the health system, emphasising the importance of leadership, systems resilience, nonhierarchical learning and connectedness. These strategies included regular and systematic engagement with organised labour, different ways of gauging and responding to staff morale, and daily 'huddles' for raid learning and responsive action. We propose three transformational actions that could deliver health systems that protect staff during good times and in times of system shocks. (a) Continuously invest in building the foundations of system resilience in good times, to draw on in an acute crisis situation. (b) Provide consistent leadership for an explicit commitment to supporting health workers through decisive action across the system. (c) Optimise available resources and partners, act on improvement ideas and obstacles. Build trusting relationships amongst and across actors.