BackgroundSARS-CoV-2 has evolved to produce new variants causing successive waves of infection. Currently, six variants are being monitored by the World Health Organization that are replacing BA.5. These include BF.7 (BA.5 + R346T in spike), BQ.1 (and BQ.1.1, with BA.5 + R346T, K444T, N460K mutations in spike), BA.2.75 (including BA.2.75.2 and CH.1.1), and XBB (including XBB.1.5). BQ.1 and XBB variants are more immune evasive and have spread quickly throughout the world. Concerning the potential severity of infections caused by these variants, the present study describes the clinical characteristics and outcomes of these major variants in Maharashtra. MethodologyA total of 1,141 reverse transcriptase-polymerase chain reaction (RT-PCR)-positive SARS-CoV-2 samples, with a cycle threshold (Ct) value of less than 25, were processed for SARS-CoV-2 whole genome sequencing between July 10, 2022, and January 12, 2023. All corresponding demographic and clinical data were recorded and analyzed using Microsoft® Excel and Epi Info™. ResultsOut of the 1,141 samples sequenced, BA.2.75* (63.78%) was the predominant Omicron variant, followed by the XBB* (18.88%), BA.2.38* (4.94%), BA.5* (4.06%), BA.2.10* (3.51%), and BQ.1* (1.65%). A total of 540 cases were contacted telephonically, of whom 494 (91.48%) were symptomatic with mild symptoms. Fever (77.73%) was the most common symptom, followed by cold (47.98%), cough (42.31%), and myalgia and fatigue (18.83%). Of the 540 cases, 414 (76.67%) cases recovered at home, and 126 (23.33%) were institutionally quarantined/hospitalized. Among the home-isolated and hospitalized cases, 416 (99.76%) and 108 (87.80%), respectively, recovered with symptomatic treatment, while one (0.24%) and 15 (12.20%), respectively, succumbed to the disease. Out of the 540 cases, 491 (90.93%) were vaccinated with at least one dose of the COVID-19 vaccine, 41 (7.59%) were unvaccinated, and for eight (1.48%) cases, vaccination data was not available. ConclusionsThe current study indicates that the XBB* variant is causing mild disease in India. However, as XBB* possesses both immune-escape and infectivity-enhancing mutations, it has the potential to spread to other parts of the world rapidly. Further, anti-SARS-CoV-2 vaccination improves survival rates in COVID-19.

Background: The SARS-CoV-2 has evolved to produce new variants causing successive waves of infection. Currently, six variants are being monitored by the World Health Organization that are replacing BA.5. These include BQ.1*, BA.5 with one or several of five mutations (R346X, K444X, V445X, N450D, N460X), BA.2.75*, XBB*, BA.4.6*, and BA.2.30.2*. BQ.1 and XBB variants are more immune evasive and have spread quickly throughout the world. With the concern of the potential severity of infections caused by these variants, the present study describes the clinical characteristics and outcomes of these major variants in Maharashtra. Material and Methods: A total of 1039 Reverse Transcriptase-Polymerase Chain Reaction (RT-PCR) positive SARS-CoV-2 samples, with a cycle threshold value (Ct) less than 25, were processed for SARS-CoV-2 whole genome sequencing between 10th July 2022 and 10th December 2022. All corresponding demographic and clinical data were recorded and analyzed using MicrosoftTM ExcelTM and Epi InfoTM. Results: Out of 1039 samples sequenced, 829 (79.79%) were assigned Pango lineages, of which BA.2.75 (67.31%) was the predominant Omicron variant, followed by the XBB* (17.13%), BA.2.38* (5.43%), BA.2.10* (3.62%) and BA.5* (3.50%). A total of 494 cases were contacted telephonically, of which 455 (92.11%) were symptomatic with mild symptoms. Fever (78.46%) was the most common symptom, followed by rhinorrhoea (46.37%), cough (42.20%), myalgia (19.56%) and fatigue (18.24%). Of the 494 cases, 379 (76.72%) cases recovered at home, and 115 (23.28%) were institutionally quarantined/ hospitalized. Among the home-isolated and hospitalized cases, 378 (99.74%) and 101 (87.83%) recovered with symptomatic treatment, whereas 01 (0.26%) and 14 (12.17%) succumbed to the disease, respectively. Of the 494 cases, 449 (90.89%) were vaccinated with at least one dose of the COVID-19 vaccine, 40 (8.10%) were unvaccinated, and for 05 (1.01%) cases, vaccine data was not available. Conclusion: The current study indicates that the XBB* variant is causing mild disease in India. However, as XBB* possess both immune-escape and infectivity-enhancing mutations, it has the potential to spread to other parts of the world rapidly.