The Centre has asked a 12-member medical panel to set clinical criteria to determine who among people with comorbidities, or underlying chronic health disorders, would be eligible to receive vaccines against the coronavirus disease on priority.

The National Expert Group on Covid-19 vaccination strategies that has recommended vaccines on priority for four categories of people will rely on the panel’s suggestions to assign vaccines to people with underlying health disorders aged below 50 years.

The expert group had earlier this month recommended that around 10 million healthcare workers, 20 million frontline workers, and an estimated 270 million people aged above 50 years and those below 50 with comorbidities should be prioritised for the vaccines.

The medical panel that includes specialists in cancer, cardiovascular, kidney disease and other chronic disorders has been tasked with formulating clinical criteria and guidelines that would allow people with comorbidities to register for the vaccination campaigns.

“We’re expecting their report within the next few days,” Vinod Paul, the chair of the national expert group on Covid-19 vaccination, said on Tuesday. The panel has been asked to take into account the severity of the underlying illness and its likely impact on the course of the Covid-19 infection.

“Mild hypertension (high blood pressure) which is prevalent in about 30 per cent of adults may or may not be a case for (vaccine) entitlement, but severe hypertension would be,” Paul said. The criteria would seek to ensure those at high risk of severe Covid-19 or death are prioritised for early vaccination.

A senior epidemiologist guiding the Centre’s vaccination strategy told The Telegraph that the four priority groups have been chosen on the basis of either their occupational risk of exposure to Covid-19 or their risk of developing severe disease or dying from Covid-19.

Studies worldwide have found Covid-19 patients with comorbidities at high risk of severe disease.

“I think all people with combinations of certain comorbidities such as a combination of high blood pressure, obesity and diabetes would need to be included in the priority group,” said Ambrish Mithal, a senior endocrinologist in New Delhi, who is not part of the medical panel.

Mithal and his colleagues who analysed the clinical outcomes of 401 hospitalised Covid-19 patients in Delhi found that high blood pressure was the most common shared comorbidity in patients with diabetes and 12 out of 15 patients who died had diabetes.

India’s drug regulatory authority is currently evaluating applications for the emergency use authorisation of three Covid-19 vaccines — the AstraZeneca-Oxford vaccine produced in India by the Serum Institute of India, a homegrown vaccine from Bharat Biotech and Pfizer’s vaccine.

Some health experts have predicted that at least one of these vaccines is likely to be approved within days and the immunisation campaign would be launched in January. The Union health ministry has already conducted mock vaccination drills in Assam, Andhra Pradesh, Punjab and Gujarat as part of efforts to prepare local health staff for the immunisation campaign.

Operational guidelines for the vaccination campaign list multiple sub-categories of healthcare workers and frontline workers. Healthcare workers would include nurses, doctors, paramedical, support and sanitary staff, students and researchers in healthcare institutions, while frontline workers would include defence, central and state police, and all sub-categories of municipal workers.