Clinical and experimental evidence suggest omicron variant of SARS-CoV-2 is inherently less pathogenic than delta variant independent of previous immunity

European Journal of Medical Research

Research

Anil K. Pandey¹  Sweety Samal²  Amit Awasthi²  Nitya Wadhwa²  Sreevatsan Raghavan²  Ramachandran Thiruvengadam²  Mudita Gosain²  Zaigham Abbas Rizvi²  Pramod Kumar Garg²  Shinjini Bhatnagar²  Jyotsna Dandotiya²  Deepika Rathna Murugesan² 

[1] ESIC Medical College and Hospital, Faridabad, India;Translational Health Science and Technology Institute, Faridabad, Delhi, India;

关键词: Omicron;    SARS-CoV-2;    COVID-19;    hamster;    hACE2 transgenic mice;   

DOI  :  10.1186/s40001-023-01373-3

 received in 2022-11-10, accepted in 2023-09-18,  发布年份 2023

来源: Springer

【 摘 要 】

ObjectivesTo study clinical disease outcomes in both human and animal models to understand the pathogenicity of omicron compared to the delta variant.MethodsIn this cross-sectional observational study, clinical outcomes of adults who tested positive at 2 testing centres in Delhi National Capital Region between January 2022 and March 2022 (omicron-infected; N = 2998) were compared to a similar geographical cohort (delta-infected; N = 3292). In addition, disease course and outcomes were studied in SARS-CoV-2-infected golden Syrian hamsters and K-18 humanized ACE2 transgenic mice.ResultsOmicron variant infection was associated with a milder clinical course [83% (95% CI 61, 94) reduced risk of severity compared against delta] adjusting for vaccination, age, sex, prior infection and occupational risk. This correlated with lower disease index and vir comparing omicron with other variants in animal models.ConclusionsInfections caused by the omicron variant were milder compared to those caused by the delta variant independent of previous immunity.

【 授权许可】

CC BY   
© BioMed Central Ltd., part of Springer Nature 2023

【 图 表 】

Fig. 4