A comparative study on epidemiological characteristics, transmissibility, and pathogenicity of three COVID-19 outbreaks caused by different variants.

Academic Journal

Liu, Chan¹ (AUTHOR) 511353697@qq.com
Lu, Jianhua^1,2 (AUTHOR) 25430557@qq.com
Li, Peihua¹ (AUTHOR) m18025339965@163.com
Feng, Siyang² (AUTHOR) siyangfeng@163.com
Guo, Yichao¹ (AUTHOR) 564931539@qq.com
Li, Kangguo¹ (AUTHOR) kanggle@outlook.com
Zhao, Benhua¹ (AUTHOR) benhuazhao@163.com
Su, Yanhua¹ (AUTHOR) suyanhua813@xmu.edu.cn
Chen, Tianmu¹ (AUTHOR) 13698665@qq.com
Zou, Xuan^1,2 (AUTHOR) 914494557@qq.com

International Journal of Infectious Diseases. Sep2023, Vol. 134, p78-87. 10p.

*SARS-CoV-2 Omicron variant
*SARS-CoV-2 Delta variant
*COVID-19 pandemic
*DISTRIBUTION (Probability theory)
*SARS-CoV-2

• Transmissibility of three variants was Omicron BA.2>Omicron BA.1 > Delta. • Omicron BA.2 variant has less pathogenicity than Omicron BA.1 and Delta variant. • Transmissibility in cycle threshold value should be discussed in further research. The Omicron BA.2 variant is probably the main epidemic strain worldwide at present. Comparing the epidemiological characteristics, transmissibility, and influencing factors of SARS-CoV-2, the results obtained in this paper will help to provide theoretical support for disease control. This study was a historical information analysis, using the R programming language and SPSS 24.0 for statistical analysis. The Geoda and Arc GIS were used for spatial autocorrelation analysis. Local spatial autocorrelations of the incidence rate were observed in Delta and Omicron BA.1 outbreaks, whereas Omicron BA.2 outbreaks showed a random distribution in incidence rate. The time-dependent reproduction number of Delta, Omicron BA.1, and Omicron BA.2 were 3.21, 4.29, and 2.96, respectively, and correspondingly, the mean serial interval were 4.29 days (95% confidence interval [CI]: 0.37-8.21), 3.84 days (95% CI: 0-8.37), and 2.77 days (95% CI: 0-5.83). The asymptomatic infection rate of cases in Delta, Omicron BA.1, and Omicron BA.2 outbreaks were 21.71%, 6.25%, and 4.35%, respectively. The Omicron BA.2 variant had the greatest serial interval, transmissibility, and transmission speed, followed by BA.1, and then Delta. Compared with Delta and Omicron BA.1 variants, the Omicron BA.2 variant may be less pathogenic and more difficult to control than Omicron BA.1 and Delta. [ABSTRACT FROM AUTHOR]