28 augustus 2021: Bron: The Lancet

Een grote landelijke Engelse studie vond een hoger risico op ziekenhuisopname of spoedeisende hulp voor patiënten met COVID-19 die besmet waren met de delta-variant in vergelijking met de alfa-variant. Uit een totale groep van patiënten (N =  43.338 mensen) die waren besmet met COVID-19 (N = 8682 met de delta-variant, N = 34.656 met de alfa-variant; mediane leeftijd 31 jaar [IQR 17-43]) werden opgenomen in een analyse. 

498 patiënten met de delta-variant (5,7%) versus 1448 patiënten met de alfa-variant (4,2%) werden binnen 14 dagen na de eerste positieve test opgenomen in het ziekenhuis of gingen naar de spoedeisende hulp.
De meeste patiënten waren niet gevaccineerd (32 078 [74,0%] in beide groepen, maar dus nog altijd 26 procent van de gevaccineerden werd ook ernstig ziek). En toch wel opvallend: het verschil tussen de Delta variant en de Alfa variant was voor beide groepen, gevaccineerd of niet gevaccineerd, nagenoeg gelijk. (2·32 [1·29–4·16] and 1·43 [1·04–1·97]; p=0·82 voor beide groepen).

Conclusie van de onderzoekers:

Deze grote landelijke studie vond een hoger risico op ziekenhuisopname of spoedeisende hulp voor patiënten met COVID-19 die besmet waren met de delta-variant in vergelijking met de alfa-variant. Resultaten suggereren dat uitbraken van de delta-variant in niet-gevaccineerde populaties kunnen leiden tot een grotere belasting van de gezondheidszorg dan de alfa-variant.

Het studierapport is gepubliceerd in the Lancet. Klik op de titel van het abstract voor het gratis studieverslag.

Hospital admission and emergency care attendance risk for SARS-CoV-2 delta (B.1.617.2) compared with alpha (B.1.1.7) variants of concern: a cohort study

Open AccessPublished:August 27, 2021DOI:https://doi.org/10.1016/S1473-3099(21)00475-8



The SARS-CoV-2 delta (B.1.617.2) variant was first detected in England in March, 2021. It has since rapidly become the predominant lineage, owing to high transmissibility. It is suspected that the delta variant is associated with more severe disease than the previously dominant alpha (B.1.1.7) variant. We aimed to characterise the severity of the delta variant compared with the alpha variant by determining the relative risk of hospital attendance outcomes.


This cohort study was done among all patients with COVID-19 in England between March 29 and May 23, 2021, who were identified as being infected with either the alpha or delta SARS-CoV-2 variant through whole-genome sequencing. Individual-level data on these patients were linked to routine health-care datasets on vaccination, emergency care attendance, hospital admission, and mortality (data from Public Health England's Second Generation Surveillance System and COVID-19-associated deaths dataset; the National Immunisation Management System; and NHS Digital Secondary Uses Services and Emergency Care Data Set). The risk for hospital admission and emergency care attendance were compared between patients with sequencing-confirmed delta and alpha variants for the whole cohort and by vaccination status subgroups. Stratified Cox regression was used to adjust for age, sex, ethnicity, deprivation, recent international travel, area of residence, calendar week, and vaccination status.


Individual-level data on 43 338 COVID-19-positive patients (8682 with the delta variant, 34 656 with the alpha variant; median age 31 years [IQR 17–43]) were included in our analysis. 196 (2·3%) patients with the delta variant versus 764 (2·2%) patients with the alpha variant were admitted to hospital within 14 days after the specimen was taken (adjusted hazard ratio 2·26 [95% CI 1·32–3·89]). 498 (5·7%) patients with the delta variant versus 1448 (4·2%) patients with the alpha variant were admitted to hospital or attended emergency care within 14 days (adjusted HR 1·45 [1·08–1·95]). Most patients were unvaccinated (32 078 [74·0%] across both groups). The HRs for vaccinated patients with the delta variant versus the alpha variant (adjusted HR for hospital admission 1·94 [95% CI 0·47–8·05] and for hospital admission or emergency care attendance 1·58 [0·69–3·61]) were similar to the HRs for unvaccinated patients (2·32 [1·29–4·16] and 1·43 [1·04–1·97]; p=0·82 for both) but the precision for the vaccinated subgroup was low.


This large national study found a higher hospital admission or emergency care attendance risk for patients with COVID-19 infected with the delta variant compared with the alpha variant. Results suggest that outbreaks of the delta variant in unvaccinated populations might lead to a greater burden on health-care services than the alpha variant.


Medical Research Council; UK Research and Innovation; Department of Health and Social Care; and National Institute for Health Research.


  1. 1.
    • WHO
    Tracking SARS-CoV-2 variants.
    Date: May 31, 2021
    Date accessed: June 6, 2021
  2. 2.
    • Davies NG 
    • Abbott S 
    • Barnard RC 
    • et al.
    Estimated transmissibility and impact of SARS-CoV-2 lineage B.1.1.7 in England.
    Science. 2021; 372eabg3055
  3. 3.
    • Volz E 
    • Mishra S 
    • Chand M 
    • et al.
    Assessing transmissibility of SARS-CoV-2 lineage B.1.1.7 in England.
    Nature. 2021; 593266-269
  4. 4.
    • Public Health England
    SARS-CoV-2 variants of concern and variants under investigation in England: technical briefing 6.
  5. 5.
    • O'Toole Á 
    • Hill V 
    • Pybus OG 
    • et al.
    Tracking the international spread of SARS-CoV-2 lineages B.1.1.7 and B.1.315/501Y-V2 [version 1; peer review: 3 approved].
    Wellcome Open Res. 2021; 6121
  6. 6.
    • Singh J 
    • Rahman SA 
    • Ehtesham NZ 
    • Hira S 
    • Hasnain SE
    SARS-CoV-2 variants of concern are emerging in India.
    Nat Med. 2021; 271131-1133
  7. 7.
    • European Centre for Disease Prevention and Control
    Emergence of SARS-CoV-2 B.1.617 variants in India and situation in the EU/EEA.
  8. 8.
    • Dhar MS 
    • Marwal R 
    • Radhakrishnan V 
    • et al.
    Genomic characterization and epidemiology of an emerging SARS-CoV-2 variant in Delhi, India.
    medRxiv. 2021; (published online June 3.(preprint version 1).
  9. 9.
    • Public Health England
    SARS-CoV-2 variants of concern and variants under investigation in England: technical briefing 15.
  10. 10.
    • Public Health England
    SARS-CoV-2 variants of concern and variants under investigation in England: technical briefing 13.
  11. 11.
    • Lopez-Bernal J 
    • Andrews N 
    • Gower C 
    • et al.
    Effectiveness of COVID-19 vaccines against the B.1.617.2 variant.
    N Engl J Med. 2021; (published online July 21.)
  12. 12.
    • Stowe J 
    • Andrews N 
    • Gower C 
    • et al.
    Effectiveness of COVID-19 vaccines against hospital admission with the delta (B.1.617.2) variant.
    khub. 2021; (published online June 14.(preprint).
  13. 13.
    • Department of Health and Social Care
    Coronavirus (COVID-19) listed as a notifiable disease.
  14. 14.
    • Clare T 
    • Twohig KA 
    • O'Connell A-M 
    • Dabrera G
    Timeliness and completeness of laboratory-based surveillance of COVID-19 cases in England.
    Public Health. 2021; 194163-166
  15. 15.
    • Connor TR 
    • Loman NJ 
    • Thompson S 
    • et al.
    CLIMB (the Cloud Infrastructure for Microbial Bioinformatics): an online resource for the medical microbiology community.
    Microb Genom. 2016; 2e000086
  16. 16.
    COVID-19 Genomics UK (COG-UK) consortiumcontact@cogconsortium.uk. An integrated national scale SARS-CoV-2 genomic surveillance network.
    Lancet Microbe. 2020; 1e99-100
  17. 17.
    • PHE Genomics
    Standardised variant definitions.
    Date: May 28, 2021
    Date accessed: June 15, 2021
  18. 18.
    • Graphnet
    National immunisation management system.
  19. 19.
    • NHS Digital
    Secondary uses service (SUS).
  20. 20.
    • NHS Digital
    Emergency care data set (ECDS).
  21. 21.
    • Brown AE 
    • Heinsbroek E 
    • Kall MM 
    • et al.
    Epidemiology of confirmed COVID-19 deaths in adults, England, March–December 2020.
    Emerg Infect Dis. 2021; 271468-1471
  22. 22.
    • Iacobucci G
    Covid-19: Local councils initiate surge vaccination to tackle B.1.617.2 variant.
    BMJ. 2021; 373n1361
  23. 23.
    • Pijls BG 
    • Jolani S 
    • Atherley A 
    • et al.
    Demographic risk factors for COVID-19 infection, severity, ICU admission and death: a meta-analysis of 59 studies.
    BMJ Open. 2021; 11e044640
  24. 24.
    • Khawaja AP 
    • Warwick AN 
    • Hysi PG 
    • et al.
    Associations with COVID-19 hospitalisation amongst 406,793 adults: the UK Biobank prospective cohort study.
    medRxiv. 2020; (published online May 11.(preprint).
  25. 25.
    • Herbert A 
    • Wijlaars L 
    • Zylbersztejn A 
    • Cromwell D 
    • Hardelid P
    Data resource profile: hospital episode statistics admitted patient care (HES APC).
    Int J Epidemiol. 2017; 46 (1093i)1093
  26. 26.
    • Bhaskaran K 
    • Bacon S 
    • Evans SJ 
    • et al.
    Factors associated with deaths due to COVID-19 versus other causes: population-based cohort analysis of UK primary care data and linked national death registrations within the OpenSAFELY platform.
    Lancet Reg Health Eur. 2021; 6100109
  27. 27.
    • NHS Digital
    COVID oximetry @home—digital and data services.
  28. 28.
    • COVID-19 Genomics UK Consortium
    Summary report: COG-UK geographic coverage of SARS-CoV-2 sample sequencing.
  29. 29.
    • Hay JA 
    • Kennedy-Shaffer L 
    • Kanjilal S 
    • et al.
    Estimating epidemiologic dynamics from cross-sectional viral load distributions.
    Science. 2021; 373eabh0635
  30. 30.
    • Sheikh A 
    • McMenamin J 
    • Taylor B 
    • Robertson C
    SARS-CoV-2 Delta VOC in Scotland: demographics, risk of hospital admission, and vaccine effectiveness.
    Lancet. 2021; 3972461-2462
  31. 31.
    • Dabrera G 
    • Allen H 
    • Zaidi A 
    • et al.
    Assessment of mortality and hospital admissions associated with confirmed infection with SARS-CoV-2 variant of concern VOC-202012/01 (B.1.1.7) a matched cohort and time-to-event analysis.
    SSRN. 2021; (published online March 22.(preprint).
  32. 32.
    • Nyberg T 
    • Twohig KA 
    • Harris RJ 
    • et al.
    Risk of hospital admission for patients with SARS-CoV-2 variant B.1.1.7: cohort analysis.
    BMJ. 2021; 373n1412
  33. 33.
    • Funk T 
    • Pharris A 
    • Spiteri G 
    • et al.
    Characteristics of SARS-CoV-2 variants of concern B.1.1.7, B.1.351 or P.1: data from seven EU/EEA countries, weeks 38/2020 to 10/2021.
    Euro Surveill. 2021; 262100348


Linked Articles

Plaats een reactie ...

Reageer op "Delta mutatie van het coronavirus (Covid-19) geeft 2x zo groot risico (bijna 6 procent vs 4 procent) op ernstige ziekte dan de Alpha mutatie."

Gerelateerde artikelen

Gerelateerde artikelen

Er stierven in Japan beduidend >> Dr. Sabine Hazan mocht eindelijk >> Booster vaccinaties lijken >> Maurice de Hond geeft commentaar >> Opsluiting van kwetsbare mensen >> mRNA vaccinatie tegen coronavirus >> Vitamine-C infusen met hoge >> Hydroxychloroquine plus azithromycine >> Oversterfte in Nederland en >> Oversterfte in Duitsland is >>