A vial of the Oxford University-AstraZeneca COVID-19 vaccine, which is produced in India and marketed as Covishield (Image: Reuters/Gleb Garanich)
The Centre on May 13 accepted the recommendation made by an expert panel to increase the gap between two Covishield vaccine doses to 12-16 weeks.
The two jabs of the Serum Institute of India (SII)-manufactured vaccine were earlier administered at a gap of six-to-eight weeks.
The increase in dosage interval was suggested by the National Technical Advisory Group on Immunisation (NTAGI) to the Centre's COVID-19 Working Group, claiming that it would provide "better results".
Based on the available real-life evidences, particularly from the UK, the COVID-19 Working Group agreed for increasing the interval to 12-16 weeks between two doses of Covishield vaccine, the Union Health Ministry stated in an official release.
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The recommendation of COVID-19 Working Group - to increase the Covishield dose interval gap - was accepted by the National Expert Group on Vaccine Administration for Covid-19 (NEGVAC), the top government advisory body, on May 12. Subsequently, the Union Health Ministry also gave its nod.
"The Union Ministry of Health and Family Welfare has accepted the recommendation of the COVID Working Group for extension of the gap between the first and second doses of Covishield vaccine to 12 -16 weeks," the official release stated.
The COVID-19 Working Group, however, has not recommended any change in interval of Covaxin vaccine doses which are administered at a gap of four to six weeks.
Notably, Covaxin and Covishield are the two vaccines being currently administered to beneficiaries in India. The dose interval gap for the latter was increased from 28 days to six-to-eight weeks in March, based on the recommendation of the World Health Organisation (WHO). With the fresh revision, it has now been further extended to 12-16 weeks.
The decision to increase the gap also comes amid reports of vaccine shortages in a number of states. Maharashtra, the state worst-affected by the second pandemic wave, announced on May 11 that it would be prioritising the second doses for 45-plus age group by temporarily pausing the immunisation drive for 18-44 age group.
The extension in dose interval gap is expected to beneficial for India on two fronts - it can reduce the stress on state governments as it provides more time to procure the vaccine for second dose, and would also provide enhanced immunity, as claimed by the experts' panel.
The NTAGI's suggestion to increase the gap interval also comes a couple of months after a study, published in The Lancet
in March, claimed that the Oxford-AstraZeneca vaccine - known as Covishield in India - can provide 81.3 percent efficacy if doses are administered at 12 weeks apart.