India will resume exports of Covid-19 vaccines in the October quarter, prioritising the global vaccine-sharing platform COVAX and neighbouring countries first as supplies rise, the health minister said on Monday.

India, the world's biggest maker of vaccines, stopped exports of Covid shots in April to focus on inoculating its own population as infections exploded.

The country's monthly vaccine output has since more than doubled and is set to quadruple to over 300 million doses next month, minister Mansukh Mandaviya said, adding that only excess supplies would be exported.

Total production could top 1 billion in the last three months of the year as new vaccines from companies such as Biological E are likely to be approved, he said.

"We will help other countries and also fulfil our responsibility towards COVAX," he told reporters.

Reuters reported last week that India was considering restarting exports of Covid-19 vaccines soon. It donated or sold 66 million doses to nearly 100 countries before the export halt. 

The announcement on resumption of exports in the October to December quarter comes ahead of Prime Minister Narendra Modi's visit to Washington this week where vaccines are likely to be discussed at a summit of the leaders of the Quad countries - the United States, India, Japan and Australia.

India wants to vaccinate all its 944 million adults by December and has so far given at least one dose to 64% of them and two doses to 22%.

India's inoculations have jumped since last month, especially as the world's biggest vaccine maker, the Serum Institute of India, has more than trebled its output of the AstraZeneca shot to 200 million doses a month from April levels.

Indian companies have set up the capacity to produce nearly 3 billion Covid vaccine doses a year.