Coronavirus | Extending gap between Covishield doses scientific: V.K. Paul

It was taken by consensus by a group of experts. Dr. Paul says.

Updated - November 30, 2021 06:33 pm IST

Published - May 15, 2021 11:53 pm IST - NEW DELHI

Recipients wait outside a vaccination centre in Vijayawada to receive their second dose COVID-19 jab of on May 15, 2021.

Recipients wait outside a vaccination centre in Vijayawada to receive their second dose COVID-19 jab of on May 15, 2021.

The decision to delay the second dose of Covishield vaccine to up to 16 weeks was not due to a “shortage” of vaccines but was based on scientific evidence from the U.K., said V.K. Paul, Chairman, National Expert Group on Vaccine Administration for COVID-19, on Saturday. It was taken by consensus by a group of experts , he said.

Dr. Paul said it was “sad” that there were “narratives” that the decision was taken adhoc and due to shortages.


“The standard protocol of vaccine administration is 4-6 weeks. When the U.K. decided to delay their second dose, there was little scientific evidence to justify it at that time. That’s why our own recommendation was first 4-6 weeks and based on newer evidence, it was increased to 6-8 weeks. However, evidence from there has shown that their decision to delay the second dose upto three months has seen 65%-85% protection against severe disease. Also, there was a definite break in transmission of the disease. So that’s the evidence considered by the committee to expand dosage interval,” he said during a press briefing.

Dr. N.K. Arora, who heads the expert group tasked with recommending the appropriate interval between doses, seconded Dr. Paul. Delaying a second dose by a month or two wasn’t a solution to address the shortage if the overall supply didn’t improve, he told The Hindu in a phone conversation. He said he expected a significant increase in supply only by August.

Also read | Covaxin, Covishield still potent against B.1.617 strain but produces fewer antibodies

“However we’ve recommended a vaccine ‘sparing strategy’ and it is likely to be announced by the government next week,” he stated.

While Dr. Arora didn’t explain what such strategy was, he said it would apply to all future supply and was designed to make the entire vaccine supply process “more efficient.” From August, the expectation was that there would be 27 crore doses available a month with increased supply of Covaxin, Covishield and Sputnik V. “By December, I’m confident that we’ll even have enough to give our neighbouring countries.”

WHO panel recommendation

In February, an expert panel of the World Health Organisation recommended an 8-12 week interval between two doses of the AstraZeneca. Clinical trials had shown that vaccines 4-6 weeks apart had around 54% efficacy compared to 79% if the gap was 12 weeks.

India currently averages between 2-2.5 million doses a day with over 65% of them given to those over 45. Though open to all and with an option to access paid doses, it’s a challenge for adults below 44 to find a slot for the first shot.

Also read | Updated efficacy results show benefits of delaying second dose of Oxford vaccine

Dr. Arora said that vaccination ideally ought not to have been made available for those below 45 as the risks from the disease— even after the second wave— continued to be much higher for those older as in the first wave.

On Saturday, the Department of Biotechnology (DBT) said discussions were on between the Gujarat Biotechnology Research Centre, Hester Biosciences and OmniBRx and Bharat Biotech to scale up the Covaxin technology and to produce minimum 20 million doses a month.

Bharat Biotech had been funded ₹65 crore by the DBT to expand its manufacturing to 10 crore doses a month by September. Haffkine Biopharmaceutical Corporation Ltd, Mumbai, had been given ₹65 crore as grant from the Government of India to make 2 crore doses a month; Indian Immunologicals Limited (IIL), Hyderabad –a facility under the National Dairy Development Board, is being provided ₹60 crore; and Bharat Immunologicals and Biologicals Limited (BIBCOL), Bulandshahr, a CPSE under the DBT, is being supported with a grant of ₹30 crore to prepare their facility to provide 10-15 million doses a month.

While recommending increasing the Covishield dosing interval to 12-16 weeks, the panel suggested no change in the interval of Covaxin doses. The panel also recommended that those infected with COVID-19 should be administered a vaccine after six months and people who had received plasma during treatment should get vaccinated at least after 12 weeks.

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