ArticleClinical infectious diseases : an official publication of the Infectious Diseases Society of America2022
Clinical and Virological Features of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) Variants of Concern: A Retrospective Cohort Study Comparing B.1.1.7 (Alpha), B.1.351 (Beta), and B.1.617.2 (Delta).
Article in Clinical infectious diseases : an official publication of the Infectious Diseases Society of America, 2022. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 273 papers, 3 of them syntheses that pooled it.
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273 citing papers in PubMed, 3 syntheses or guidelines pooled it, 417 citations in OpenAlex.
- Association of hypernatremia with mortality in patients with COVID-19: A systematic review and meta-analysis.Immunity, inflammation and disease · 2023Pooled it
- Electrolyte imbalances as poor prognostic markers in COVID-19: a systemic review and meta-analysis.Journal of endocrinological investigation · 2023Pooled it
- COVID-19 Convalescent Plasma for the Treatment of Immunocompromised Patients: A Systematic Review and Meta-analysis.JAMA network open · 2023Pooled it
- Decreased Efficiency of Neutralizing Antibodies from Previously Infected or Vaccinated Individuals against the B.1.617.2 (Delta) SARS-CoV-2 Variant.Microbiology spectrum · 2022Trial
- Baseline cohort profile: clinical and molecular characterisation of SARS-CoV-2 infected patients recruited into a longitudinal COVID-19 cohort study (COVGEN) in Malaysia.BMC infectious diseases · 2026Article
- Immune Priming and the Risk of COVID-19, Influenza, and Other Acute Respiratory Infections: Insights From an N3C Cohort.Influenza and other respiratory viruses · 2026Article
- A comprehensive assessment of the impact of COVID variant and vaccination on venous thromboembolism and mortality.Research and practice in thrombosis and haemostasis · 2026Article
- Observational
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- An outlook on clinical and demographic variables in patients with severe COVID-19 across different waves in Mexico and SARS-CoV-2 variants: data from two high-specialty centers.Frontiers in public health · 2026Article
- Impact of COVID-19 on Renal Function: Analysis of Acute Kidney Injury Across Three Pandemic Waves.Biomedicines · 2025Article
- A public health perspective of SARS-CoV-2 evolution and surveillance strategies in Germany from 2020 to 2023.Communications medicine · 2025Review
- Severe acute respiratory syndrome coronavirus 2-mediated dysregulation of drug processing genes is dependent on pathogenic variants, target site of infection, age, and sex.Drug metabolism and disposition: the biological fate of chemicals · 2025Article
- Dissecting Sex-Specific Pathology in K18-hACE2 Transgenic Mice Infected With Different SARS-CoV-2 Variants.Journal of medical virology · 2025Article
- Is SARS-CoV-2 facing constraints in its adaptive evolution?Biomolecules & biomedicine · 2025Review
- EIDD-2801 resists to infection and co-infection of SARS-CoV-2 and influenza virus.Virology journal · 2025Article
- Tracking vaccine effectiveness in an evolving pandemic, countering misleading hot takes and epidemiologic fallacies.American journal of epidemiology · 2025Article
- Comparative Interactome Profiling of Nonstructural Protein 3 Across SARS-CoV-2 Variants Emerged During the COVID-19 Pandemic.Viruses · 2025Article
- Quasi-species prevalence and clinical impact of evolving SARS-CoV-2 lineages in European COVID-19 cohorts, January 2020 to February 2022.Euro surveillance : bulletin Europeen sur les maladies transmissibles = European communicable disease bulletin · 2025Article
- Association between COVID-19 vaccination, SARS-CoV-2 variants, and post COVID-19 condition: A cross-sectional study.PloS one · 2025Article
213 more citing papers are in PubMed but not listed here.
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Authors and funding
16 authors at 6 institutions in 1 country.
Funding
No grant is acknowledged in the PubMed record.
Abstract
backgroundThe impact of SARS-CoV-2 variants of concern (VOCs) on disease severity is unclear. In this retrospective study, we compared the outcomes of patients infected with B.1.1.7, B.1.351, and B.1.617.2 with wild-type strains from early 2020.
methodsNational surveillance data from January to May 2021 were obtained and outcomes in relation to VOCs were explored. Detailed patient-level data from all patients with VOC infection admitted to our center between December 2020 and May 2021 were analyzed. Clinical outcomes were compared with a cohort of 846 patients admitted from January to April 2020.
resultsA total of 829 patients in Singapore in the study period were infected with these 3 VOCs. After adjusting for age and sex, B.1.617.2 was associated with higher odds of oxygen requirement, intensive care unit admission, or death (adjusted odds ratio [aOR], 4.90; 95% confidence interval [CI]: 1.43-30.78). Of these patients, 157 were admitted to our center. After adjusting for age, sex, comorbidities, and vaccination, the aOR for pneumonia with B.1.617.2 was 1.88 (95% CI: .95-3.76) compared with wild-type. These differences were not seen with B.1.1.7 and B.1.351. Vaccination status was associated with decreased severity. B.1.617.2 was associated with significantly lower polymerase chain reaction cycle threshold (Ct) values and longer duration of Ct value ≤30 (median duration 18 days for B.1.617.2, 13 days for wild-type).
conclusionsB.1.617.2 was associated with increased severity of illness, and with lower Ct values and longer viral shedding. These findings provide impetus for the rapid implementation of vaccination programs.
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