AstraZeneca Plc said on Sunday Britain’s health regulator had started an accelerated review of its potential coronavirus vaccine.

“We confirm the MHRA’s (Medicines and Healthcare Products Regulatory Agency) rolling review of our potential Covid-19 vaccine,” an AstraZeneca spokesman said.

In rolling reviews, regulators are able to see clinical data in real time and have dialogue with drug makers on manufacturing processes and trials to accelerate the approval process.

The approach is designed to speed up evaluations of promising drugs or vaccines during a public health emergency.

AstraZeneca’s Covid-19 vaccine is being developed along with the University of Oxford. Bloomberg reported on Friday that MHRA had also begun an accelerated review for the Covid-19 vaccine candidate from Pfizer Inc.

AstraZeneca and Pfizer are among the frontrunners in the race to develop a vaccine for the coronavirus, with the race also including Johnson & Johnson and Moderna Inc. Their vaccine candidates are in late-stage trials, interim data from which are expected in the coming weeks.

The British drug maker said on Monday its Covid-19 experimental vaccine produces an immune response in both old and young adults. The vaccine also triggers lower adverse responses among the elderly, it said.

The novel coronavirus has killed more than 1.19 million people globally, damaged the world economy and turned normal life upside down for billions of people.

Work began on the Oxford vaccine in January. Called AZD1222 or ChAdOx1 nCoV-19, the viral vector vaccine is made from a weakened version of a common cold virus that causes infections in chimpanzees.