XBB1.16 sub-variant most predominant in India: Study
According to a recent study, the clinical features and outcomes of XBB.1.16 infected patients are identical to those of other co-circulating Omicron lineage-infected individuals
PUNE

While India has seen an increase in Covid-19 cases in recent months, researchers have discovered that the XBB1.16 Omicron recombinant sub-variant has become the most prevalent SARS-CoV-2 lineage in India.
According to a recent study, the clinical features and outcomes of XBB.1.16 infected patients are identical to those of other co-circulating Omicron lineage-infected individuals.
The research was carried out in Maharashtra as part of the Indian SARS-CoV-2 Genomics Consortium (INSACOG) sequencing activity to understand the evolution of the SARS-CoV-2 virus and its epidemiological trends.
During the investigation, genome sequences of the SARS-CoV-2 virus were retrieved from the Global Initiative on Sharing Avian Influenza Data (GISAID) database, which had been deposited from various Indian states and union territories between the 1st of December 2022 and the 8th of April 2023.
The sequences were curated, then lineage and phylogenetic analysis were performed, and demographic and clinical data from Maharashtra were acquired over the phone.
On April 26, the study’s findings were published in medRxiv, a health sciences-related portal.
Dr Rajesh Karyakarte, head of the Microbiology dept at BJ Medical College, Dr Rashmita Das and Mansi Rajmane of BJMC, Krishanpal Karmodiya of Indian Institute of Science Education and Research (IISER), Dr Varsha Potdar of National Institute of Virology (NIV) and others comprise the study team.
On December 25, 2022, the XBB.1.16 lineage was first found in Indian sequences in a sample taken in Chennai.
The XBB.1.16 in India has increased from 9.30% in the fifth week of 2023 to 79.17% in the 13th week of 2023.
According to Dr Karyakarte, the state coordinator for genome sequencing, “We discovered that the XBB.1.16 sub-variant has become the most prevalent SARS-CoV-2 lineage in the country, and its clinical features and outcomes in infected patients are similar to those infected with other Omicron lineages in circulation in Maharashtra. For demographic data, the patient’s age, gender, residence, contact number, and date of specimen collection and testing were collected from Maharashtra.”
The GISAID database yielded a total of 2,944 sequences, of which 2,856 were included in the research after data curation. The XBB.1.16 lineage dominated the sequence samples from India (36.17%), followed by XBB.2.3 (12.11%) and XBB.1.5 (10.36%).
The clinical features of these 386 COVID-19 cases, 276 (71.50%) were XBB.1.16 infected patients. Most cases these patients had the symptomatic disease (92%) with mild symptoms, with fever (67%), followed by cough (42%), rhinorrhoea (33.7%), body ache (14.5%) and fatigue (14.1%) being the most common symptoms. Out of 276 cases, comorbidity was reported in 17.7% of cases, of which hypertension was the most common condition reported (47.9%), followed by diabetes mellitus (39.6%) and asthma (12.5%).
693 of the 2,856 patients were from Maharashtra, and 386 agreed to provide their clinical information and were included in the demographic and clinical study.
While the majority of XBB.1.16 infected cases were home-isolated, 25.7% required hospitalisation or institutional quarantine, with 33.8% requiring oxygen therapy. Seven (2.5%) of the 276 XBB.1.16 cases died as a result of the disease. The majority of those who died were elderly (60 years and older), had underlying comorbid illnesses, and required supplemental oxygen therapy. The clinical characteristics of COVID-19 patients infected with additional co-circulating Omicron variants were comparable to those of XBB.1.16 patients.
