Int J Biol Sci 2022; 18(5):1844-1851. doi:10.7150/ijbs.66881 This issue


B.1.617.2 (Delta) Variant of SARS-CoV-2: features, transmission and potential strategies

Yan Zhan1,2,3#, Hui Yin1,2,3#, Ji-Ye Yin1,2,3,4✉

1. Department of Clinical Pharmacology, Xiangya Hospital, Central South University, Changsha 410078, P. R. China; Institute of Clinical Pharmacology, Central South University; Hunan Key Laboratory of Pharmacogenetics, Changsha 410078, P. R. China.
2. Engineering Research Center of Applied Technology of Pharmacogenomics, Ministry of Education, 110 Xiangya Road, Changsha 410078, P. R. China.
3. National Clinical Research Center for Geriatric Disorders, 87 Xiangya Road, Changsha 410008, Hunan, P.R. China.
4. Hunan Key Laboratory of Precise Diagnosis and Treatment of Gastrointestinal Tumor, Changsha 410078, P. R. China.
#These authors contributed equally to this work.

This is an open access article distributed under the terms of the Creative Commons Attribution License ( See for full terms and conditions.
Zhan Y, Yin H, Yin JY. B.1.617.2 (Delta) Variant of SARS-CoV-2: features, transmission and potential strategies. Int J Biol Sci 2022; 18(5):1844-1851. doi:10.7150/ijbs.66881. Available from

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Graphic abstract

Coronavirus disease 2019 (COVID-19) caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has become a pandemic. With the continuous evolution of the viral genome, SARS-CoV-2 has evolved many variants. B.1.617.2, also called Delta, is one of the most concerned variants. The Delta variant was first reported in India at the end of 2020 but has spread globally, by now, to 135 countries and is not stand still. Delta shared some mutations with other variants, and owned its special mutations on spike proteins, which may be responsible for its strong transmission and increasing virulence. Under these circumstances, a systematic summary of Delta is necessary. This review will focus on the Delta variant. We will describe all the characteristics of Delta (including biological features and clinical characteristics), analyze potential reasons for its strong transmission, and provide potential protective ways for combating Delta.

Keywords: COVID-19, B.1.617.2, Delta variants, SARS-CoV-2, transmission, vaccines, diagnosis, structural biology, immune escape