Pharmaceutical company AstraZeneca on Saturday announced that it has resumed the clinical trials of its experimental coronavirus vaccine in the United Kingdom after getting the approval from the health regulatory authority. This came four days after the late-stage trials of the vaccine was halted after a study participant developed an unexplained illness.

“Clinical trials for the AstraZeneca Oxford coronavirus vaccine, AZD1222, have resumed in the UK following confirmation by the Medicines Health Regulatory Authority that it was safe to do so,” the statement from the firm said. “The UK committee has concluded its investigations and recommended to the MHRA that trials in the UK are safe to resume.”

The vaccine, developed with University of Oxford, has been widely seen as one of the leading candidates against the infection. On September 6, the company had to pause the trials to “allow review of safety data by independent committees, and international regulators”, it said in its statement on Saturday.

“AstraZeneca and the University of Oxford, as the trial sponsor, cannot disclose further medical information,” the company said. “All trial investigators and participants will be updated with the relevant information and this will be disclosed on global clinical registries, according to the clinical trial and regulatory standards.”

Oxford’s vaccine, called AZD1222, had produced an immune response against the coronavirus and proved to be safe in early-stage clinical trials, according to trial results published in medical journal The Lancet.

Over 100 vaccines are being developed around the world to tackle the coronavirus pandemic. Globally, the coronavirus has infected more than 2.85 crore people and claimed 9,16,348 lives, according to Johns Hopkins University. Over 1.92 crore people have recovered from the infection worldwide.