New Delhi: The first shipment of Covishield - the coronavirus vaccine developed by AstraZeneca and Oxford University and manufactured by the Serum Institute - landed at Delhi's Indira Gandhi airport on Thursday.

To begin facilitating a massive airlift of Covid-19 vaccines, perhaps the largest such exercise in the world, but its manufacturer here, Serum Institute of India (SII), was still awaiting an official order to be placed by the Union government.

“We have been told verbally several times, but no official order has been placed by the government authorities yet. We have 50 million doses ready and can deliver it the day we receive the order,” SII executive director Suresh Jadhav said.

He said the company already has big orders from seven institutions across the world, but “it has not committed on these yet as SII is committed to fulfilling the Indian order on priority basis”. Another senior SII officer, too, confirmed that transportation has been held up for want of an official order.

The proposed kick start of the vaccination program will start by January 13.

The Union Health Ministry stated that the coronavirus vaccine drill will take place across 736 districts in 33 states and union territories. Bharat Biotech’s Covaxin will also set to arrive soon.

The centre has already conducted one dry run to test for potential problems ahead of vaccine delivery, and a second is underway today.

India's drugs regulator has approved Oxford's COVID-19 vaccine Covishield, manufactured by the Serum Institute of India, and the indigenously developed Covaxin of Bharat Biotech for restricted emergency use in the country.

It paves the way for the roll out of at least two vaccines in the country in the coming days.