India will offer booster doses of COVID-19 vaccine to all adults from Sunday, although free third doses will be limited to frontline workers and those older than 60 who get them at government centres.
The country has given 1.85 billion vaccine doses among its population of 1.35 billion. Of these, 82 per cent are the AstraZeneca dose made domestically and called Covishield.
Those older than 18 who received a second dose nine months ago will be eligible for the "precaution" dose, the health ministry said, using the government's term for boosters.
"Adding an extra layer of safety," Health Minister Mansukh Mandaviya said in a Twitter post flagging the decision.
The booster programme started in January, limited to frontline workers and the elderly, administering a total of 24 million doses.
When the programme is extended on Sunday, those outside these two priority categories will have to pay for the shots at privately run facilities, with no mixing and matching of vaccines allowed.
Other vaccines used in India are the domestically developed Covaxin and Corbevax, and Russia's Sputnik V.
In March Reuters reported India was considering making all adults eligible for booster doses, at a time of growing infections in some countries while some Indians found it hard to travel abroad without a third dose.