The first batch of exports will be shipped to the tiny nation of Bhutan, said the officials, who asked not to be named as the plans are not public.
Two million doses of the vaccine, developed by AstraZeneca and Oxford University and manufactured by Serum Institute of India (SII), will also be despatched to Bangladesh on Thursday, said officials briefed on the plans.
SII, the world’s largest maker of vaccines, did not immediately respond to a request for comment.
SII last week told Reuters it soon expected emergency use authorisation from the World Health Organization (WHO) for the Oxford/AstraZeneca shot, which it has been licensed to make for dozens of low- and middle-income countries.
That would pave the way for SII to begin supplies to the WHO-backed COVAX initiative aimed at fairly distributing Covid-19 shots across the world.
The Oxford/AstraZeneca vaccine, which can be stored at refrigerator temperature, is widely viewed as a more viable option for many poorer nations than shots from Pfizer and Moderna that have more onerous cold-storage requirements.
India has received requests from dozens of nations, including urgent appeals from Brazil, to begin exports of the vaccine from the SII centre in the western city of Pune.
The government, however, wanted to roll out the vaccination drive at home before launching exports, one of the sources said.
India began giving shots of the Oxford/AstraZeneca vaccine, as well as another developed by Bharat Biotech, to health workers on Saturday.
India plans to start exporting Bharat Biotech’s vaccine at a later stage.
Another source said landlocked Bhutan would get its Oxford/AstraZeneca shots free. “We will begin from tomorrow, other neighbouring countries will follow soon,” the source said.
Sri Lanka, Nepal, Myanmar and the Maldives have all made requests for early delivery of vaccines.