1. Emergence of two distinct variants of SARS-CoV-2 and an explosive second wave of COVID-19: the experience of a tertiary care hospital in Pune, India.
- Author
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Shrivastava, Shubham, Mhaske, Suhas T., Modak, Meera S., Virkar, Rashmi G., Pisal, Shamburaje S., Mishra, Akhilesh Chandra, and Arankalle, Vidya A.
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SARS-CoV-2 , *SARS-CoV-2 Delta variant , *WHOLE genome sequencing , *COVID-19 , *TERTIARY care , *MONOCLONAL antibodies , *COMPARATIVE genomics - Abstract
The emergence of novel variants of SARS-CoV-2 in several countries has been associated with increased transmissibility or reduced neutralization potential of antibodies against the Wuhan virus (wild type). From August 2021 onwards, India experienced a progressive decline in the number of active SARS-CoV-2 infections, indicative of a downward trend in the explosive second wave. This prospective study was conducted quarterly for one year (May 2020 to June 2021) at a tertiary care hospital in the city of Pune in western India. Receptor-binding domain (RBD, n = 319) and full genome (n = 20) sequences from viral-RNA-positive nasopharyngeal swabs of COVID-19 patients representing the first and second waves were used for analysis. No Brazilian, South African, or California variants were detected in this study. Until December 2020, only the wild-type strain was prevalent. Concurrent with the upsurge of the second wave in March 2021, 73% (33/45) of RBD sequences harboured L452R/E484Q mutations characteristic of the Kappa variant. In April 2021, co-circulation of Kappa (37%) and Delta (L452R/T478K, 59%) variants was recorded. During May and June 2021, the Delta variant became the predominant circulating variant, and this coincided with a significant decline in the number of COVID-19 cases. Of the 20 full genome sequences, six isolates each exhibited signature mutations of the Kappa and Delta variant. With several states witnessing a reduction in the number of COVID-19 cases, continuous monitoring of newer mutations and assessment of their effect on virus transmissibility and their impact on vaccinated or previously exposed individuals is necessary. [ABSTRACT FROM AUTHOR]
- Published
- 2022
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