India has sent half a million free doses of Covid-19 vaccine to Sri Lanka, Reuters reported while quoting officials said.

India is one of the world's biggest makers of medicines, and the vaccine produced by AstraZeneca and Oxford University is being produced at the Serum Institute of India, a private firm, in the western city of Pune.

Sri Lankan President Gotabaya Rajapaksa received the vaccine, branded as COVISHIELD, from the Indian ambassador Gopal Baglay at a ceremony at Colombo airport, Gotabaya's office said in a statement.