New Delhi: Serum Institute of India -- the world's largest vaccine maker -- on Friday said it has resumed exports of Covishield vaccine to low- and middle-income countries with the first batch of consignment leaving its Pune facility.

The vaccine maker has cumulatively produced 1.25 billion doses so far, a company statement said.

"The first batches of its COVISHIELD COVID-19 vaccine left the SII manufacturing facility in Pune earlier today, for distribution to low- and middle-income countries via the COVAX mechanism," it said.

"SII's supply of doses via COVAX is expected to increase substantially into Quarter 1 2022," it added.