Serum Institute of India, the world’s largest producer of vaccines by volume and India’s main hope of large-scale supplies, said on Monday it had lodged the first formal application for emergency use approval for AstraZeneca Plc’s Covid-19 vaccine.

The UK pharmaceutical giant is chasing rivals Pfizer Inc and Moderna Inc with a vaccine that has less stringent storage requirements and is expected to be easier to distribute and faster to scale up in production than others.

But it is also facing queries from scientists over its trial data, which showed a 1.5 dose regimen delivered more than 90% efficacy and a full two-dose regimen just 62%, both administered over two stages.

Astra said two weeks ago that it could launch an additional trial to evaluate the lower dose regimen, but Serum Institute has said it would continue to test only the two full doses as it would delay trials.

Serum Institute, seeking to deliver supplies for a domestic coronavirus outbreak that is the world’s second biggest, has said an emergency use approval could preface a full rollout by February or March.

Serum Institute CEO Adar Poonawalla tweeted that the move to apply for emergency use “will save countless lives,” but did not give any other details.

The company declined to reply to Reuters’ follow-up questions about the process.

AstraZeneca’s vaccine, called “Covishield” by Serum Institute, can be stored at two to eight degrees Celsius and distributed more easily in India, which lacks cold chain capabilities that the vaccine developed by Pfizer requires.

Poonawalla has said here the company will first focus on supplying the vaccine in India before distributing it to other countries, pricing it at 1,000 rupees per dose ($13.50) for private markets.

Governments signing large supply deals will likely buy it at lower prices. In Europe, AstraZeneca has pledged to supply 300 million doses of the vaccine for 750 million euros, pointing to a per-dose price of 2.50 euros.

Over the weekend, a top Indian government health adviser said in a TV interview that Pfizer had applied for an emergency use authorization for its vaccine in the country.

An effective vaccine is increasingly being seen critical by governments as the only way to end a pandemic that has taken more than a million lives around the world.

Britain and some other nations have pressed on with plans to roll out the AstraZeneca vaccine, while the Philippines and Thailand secured millions of doses, giving the shot a vote of confidence after experts raised questions about trial data.