Covid study shows sub-variant not severe, but Maharashtra task force chief has a warning

The assessment comes at a time when the World Health Organization (WHO) has declared that Covid-19 is no longer a global emergency. It was posted recently on medRxiv, a preprint server for health sciences.

The assessment comes at a time when the World Health Organization (WHO) has declared that Covid-19 is no longer a global emergency. It was posted recently on medRxiv, a preprint server for health sciences.

Listen to this article

00:00

1x 1.5x 1.8x

Experts at Pune’s B J Medical College, the Indian Institute of Science Education and Research (IISER), and the National Institute of Virology have said their assessment of the latest coronavirus sub-variant XBB.1.16 shows it has not caused severe infections.

However, when asked about the latest assessment, Dr Subhash Salunkhe, Chairperson, Maharashtra’s Covid-19 task force, warned against complacency. “Its increased transmissibility and immune evasive properties are alarming and hence we cannot afford to be complacent,” said Salunkhe.

Dr Rajesh Karyakarte, lead author of the study and Professor of Microbiology at B J Medical College, said the identification of a new SARS-CoV2 lineage (XBB.1.16 variant in this case) should be followed with a prompt assessment of clinical features and outcomes.

“There should be an immediate sharing of genomic data to public databases. Both these measures, clinical genomic surveillance, and detection and naming of new lineages can provide prompt evidence to aid policymakers in making informed public health decisions and interventions,” Dr Karyakarte, who is also a member of Maharashtra’s Covid-19 task force, said.

As part of the study, researchers downloaded 2944 sequences from the Global Initiative on Sharing All Influenza Data (GISAID) database (from December 1, 2022, to April 8, 2023). Of these, 2856 were included in the study and the sequences from India were dominated by the XBB.1.16 lineage (36.17 per cent) followed by XBB.2.3 (12.11 per cent) and XBB.1.5 (10.36 per cent). A total of 693 sequences were from Maharashtra and of these 386 were included in the clinical study. Of the 386 cases, 276 (71.50 per cent) were XBB.1.16.

Their findings showed that 92 per cent of those with XBB.1.16 infection in the sample size of 276 had symptomatic disease – with fever (67 per cent), cough (42 per cent), rhinorrhoea (33.7 per cent), body ache (14.5 per cent), and fatigue (14.1 per cent) being the most common symptoms. Among these cases, 91.7 per cent were vaccinated with at least one dose of the vaccine against Covid 19. Around 25.7 per cent needed hospitalisation and seven (2.5 per cent) succumbed to the disease. The majority who died were above 60 years and had comorbid conditions.

Story continues below this ad

Dr Karyakarte also pointed out that the study concerns only those cases where samples were sequenced that in turn was a subset of those who were RT-PCR tested (most were symptomatic).

Since its identification on March 4 this year, the XBB.1.16 lineage has already spread to 31 countries, with India reporting the highest percentage of sequences (32.47 per cent), followed by Brunei (4.50 per cent), and Singapore (3.21 per cent). XBB.1.16 is an XBB.1 sub-lineage characterised by unique mutations in the genome’s spike.

“The SARS-CoV-2 has undergone rapid evolution since November 2019, resulting in the emergence of competing lineages. Co-infections with different SARS-CoV-2 lineages can give rise to recombinant lineages,” Dr Karyakarte said adding their study showed that XBB.1.16 lineage had become the most predominant one in India. “However, this sub-variant has not caused severe infections. Due to the increased growth efficiency XBB.1.16 is progressively replacing all other co-circulating lineages in the country,” he added.

Rapid monitoring of the lineage’s growth rate by scientists and identifying the mutations helped understand that the sudden surge in a number of cases was due to a new, fitter, and immune evasive subvariant.

Story continues below this ad

According to Dr Krishanpal Karmodiya, Assistant Professor, IISER and one of the authors of the study, “The pandemic will eventually go down this way. This was a silent wave with not many hospitalisations. The way forward is to continue with sequencing and integrating data with hospitalisations”.

Meanwhile, Dr Ishwar Gilada, Consultant, Infectious Diseases and Secretary General Organised Medicine Academic Guild-OMAG, welcomed the WHO decision. “The pandemic ended.. it may have ripples and can be endemic here and there. I am glad that finally, wiser counsel prevailed. We have been advising WHO as well as our Government for long,” he said.

Anuradha Mascarenhas

Anuradha Mascarenhas is a Senior Editor at The Indian Express, based in Pune. With a career spanning three decades, she is one of the most respected voices in Indian journalism regarding healthcare, science and environment and research developments. She also takes a keen interest in covering women's issues . Professional Background Education: A gold medalist in Communication and Journalism from Savitribai Phule Pune University and a Master’s degree in Literature. Author: She authored the biography At The Wheel Of Research, which chronicles the life and work of Dr. Soumya Swaminathan, the former Chief Scientist at the WHO. Key Focus: She combines scientific accuracy with storytelling, translating complex medical research into compelling public and human-interest narratives. Awards and Recognition Anuradha has won several awards including the Press Council of India's national award for excellence in journalism under the gender based reporting category in 2019 and the Laadli Media award (gender sensitivity -2024). A recipient of the Lokmat journalism award (gender category-2022), she was also shortlisted for the RedInk awards for excellence in journalism-2021. Her debut book At The Wheel Of Research, an exclusive biography of Dr Soumya Swaminathan the inaugural chief scientist of World Health Organisation was also nominated in the Popular Choice Category of JK Paper AUTHER awards. She has also secured competitive fellowships including the Laadli Media Fellowship (2022), the Survivors Against TB – New Research in TB Media Fellowship (2023) and is part of the prestigious 2025 India Cohort of the WomenLift Health Leadership Journey.” Recent Notable Articles (Late 2025) 1. Cancer & Specialized Medical Care "Tata Memorial finds way to kill drug-resistant cancer cells" (Nov 26, 2025): Reporting on a breakthrough for triple-negative breast cancer, one of the most aggressive forms of the disease. Discipline, diet and purpose; How a 97-year-old professor defies ageing'' (Nov 15, 2025) Report about Prof Gururaj Mutalik, the first Head of Department at Pune's B J Government Medical College who at 97 credits his longevity to healthy habits and a strong sense of purpose. 2. Environmental Health (The "Breathless Pune" Series) Long-term exposure even to 'moderate' air leads to chronic heart, lung, kidney issues" (Nov 26, 2025): Part of an investigative series highlighting that even "safe" pollution levels are damaging to vital organs. "For every 10 µg/m3 increase in PM2.5 level, there was 6-8% jump in medicine sales" (Nov 23, 2025): Using commercial data to prove the direct link between air quality and respiratory illnesses in Pune. 3. Lifestyle & Wellness News "They didn't let cancer, diabetes and heart disease stop them from travelling" (Dec 22, 2025): A collaborative piece featuring survivors who share practical tips for traveling with chronic conditions. At 17, his BP shot up to 200/120 mmHG; Lancet study flags why child and teen hypertension doubled between 2000 and 2020'' (Nov 12,2025)--A report that focusses on 17-year-old-boy's hypertensive crisis and reflects the rising global trend of high blood pressure among children and adolescents. 4. Scientific Recognition & Infrastructure For promoting sci-comm, gender diversity: IUCAA woman prof highlighted in Nature" (Nov 25, 2025): Covering the global recognition of Indian women scientists in gender studies and physics. Pune researchers find a spiral galaxy like the Milky Way from early universe'' (December 3, 2025)- A report on how Indian researchers discovered a massive galaxy that existed when the universe was just 1.5 billion years old , one of the earliest to have been observed so far. Signature Beat: Health, Science & Women in Leadership Anuradha is known for her COVID-19 reportage, where she was one of the first journalists to provide detailed insights into the Covishield and Covaxin trials. She has a dedicated interest in gender diversity in health and science, often profiling women researchers who are breaking the "leaky pipeline" in STEM fields. Her writing style is scrupulous, often featuring interviews with top-tier scientists and health experts from various institutions. ... Read More

Click here to join Express Pune WhatsApp channel and get a curated list of our stories

Tags:
COVID-19
pune