ArticleTropical medicine & international health : TM & IH2022
Outcomes of laboratory-confirmed SARS-CoV-2 infection in the Omicron-driven fourth wave compared with previous waves in the Western Cape Province, South Africa.
Article in Tropical medicine & international health : TM & IH, 2022. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 99 papers, 5 of them syntheses that pooled it.
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Who cites it
99 citing papers in PubMed, 5 syntheses or guidelines pooled it, 130 citations in OpenAlex.
- Effectiveness of the pre-Omicron COVID-19 vaccines against Omicron in reducing infection, hospitalization, severity, and mortality compared to Delta and other variants: A systematic review.Human vaccines & immunotherapeutics · 2023Pooled it
- Severity and outcomes of Omicron variant of SARS-CoV-2 compared to Delta variant and severity of Omicron sublineages: a systematic review and metanalysis.BMJ global health · 2023Pooled it
- Role of previous infection with SARS-CoV-2 in protecting against omicron reinfections and severe complications of COVID-19 compared to pre-omicron variants: a systematic review.BMC infectious diseases · 2023Pooled it
- Severity of the Omicron SARS-CoV-2 variant compared with the previous lineages: A systematic review.Journal of cellular and molecular medicine · 2023Pooled it
- Facing the Omicron variant-how well do vaccines protect against mild and severe COVID-19? Third interim analysis of a living systematic review.Frontiers in immunology · 2022Pooled it
- Trial
- Challenges to the Effectiveness and Immunogenicity of COVID-19 Vaccines: A Narrative Review with a Systematic Approach.Vaccines · 2025Review
- Article
- Increased gastrointestinal bleeding-related mortality during the COVID-19 pandemic.Therapeutic advances in gastroenterology · 2025Article
- A risk science perspective on vaccines.Risk analysis : an official publication of the Society for Risk Analysis · 2024Article
- Clinical characteristics and booster vaccine effectiveness of the Omicron variant.BMC infectious diseases · 2024Article
- Clinical outcomes of Omicron infection and vaccine acceptance among pediatric liver transplant recipients: insights from a cross-sectional survey.Virology journal · 2024Observational
- Acute and long COVID-19 symptoms and associated factors in the omicron-dominant period: a nationwide survey via the online platform Wenjuanxing in China.BMC public health · 2024Article
- Impact of non-emergency surgical timing on postoperative recovery quality in mild or asymptomatic SARS-CoV-2 infected patients: a grouped cohort study.BMC anesthesiology · 2024Article
- Clinical characterisation, treatment outcomes, and case fatality risk of patients with different SARS-CoV-2 variants in Bangladesh.Journal of global health · 2024Observational
- Impact of COVID-19 Infection and Its Association With Previous Vaccination in Patients With Myasthenia Gravis in Korea: A Multicenter Retrospective Study.Journal of Korean medical science · 2024Article
- SARS-CoV-2 Neutralizing Antibodies in Three African Countries Following Multiple Distinct Immune Challenges.Vaccines · 2024Article
- Systemic and mucosal adaptive immunity to SARS-CoV-2 during the Omicron wave in patients with chronic lymphocytic leukemia.Haematologica · 2024Article
- Comparing COVID-19 severity in patients hospitalized for community-associated Delta, BA.1 and BA.4/5 variant infection.Frontiers in public health · 2024Article
- SARS-CoV-2 seroepidemiology in Cape Town, South Africa, and implications for future outbreaks in low-income communities.PLOS global public health · 2024Article
39 more citing papers are in PubMed but not listed here.
Corrections and comments
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Authors and funding
47 authors at 11 institutions in 2 countries.
Funding
Abstract
objectivesThe objective was to compare COVID-19 outcomes in the Omicron-driven fourth wave with prior waves in the Western Cape, assess the contribution of undiagnosed prior infection to differences in outcomes in a context of high seroprevalence due to prior infection and determine whether protection against severe disease conferred by prior infection and/or vaccination was maintained.
methodsIn this cohort study, we included public sector patients aged ≥20 years with a laboratory-confirmed COVID-19 diagnosis between 14 November and 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 hospitalisation or death and any hospitalisation or death (all ≤14 days after diagnosis) adjusted for age, sex, comorbidities, geography, vaccination and prior infection.
resultsWe included 5144 patients from wave four and 11,609 from prior waves. The 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).
conclusionsIn 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 a modest reduction in risk of severe hospitalisation or death compared to the Delta-driven wave.
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Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.