London — Oxford University announced that its COVID-19 vaccine has entered its next phases of human trials, according to a statement on Friday, as British health authorities announced that 351 more people died from the disease across the UK over the past 24 hours.

The Department of Health reported: “As of 9am 22 May, there have been 3,231,921 tests, with 140,497 tests on 21 May. 2,144,626 people have been tested of which 254,195 tested positive.

“As of 5pm on 21 May, of those tested positive for coronavirus, across all settings, 36,393 have sadly died.”

The Oxford vaccine is called ChAdOx1 nCoV-19. Phase I began in April, and saw 1,000 immunizations completed, with the follow up still ongoing. Phases II and III are now beginning, Anadolu Agency reports.

Phase II will recruit up to 10,260 people, and expand the age range of participants to include the elderly and children, those aged over 56 and those between 5 and 12 years old.

The purpose is to assess the immune response in people of different ages, and see if there are any differences in how the young and old react to the vaccine.

Phase III will assess how the vaccine works in large numbers of people above the age of 18, and how well the vaccine prevents people becoming infected and ill with COVID-19.

Andrew Pollard, the head of the Oxford Vaccine Group, said: “The clinical studies are progressing very well and we are now initiating studies to evaluate how well the vaccine induces immune responses in older adults, and to test whether it can provide protection in the wider population. We are very grateful to the huge support of the trial volunteers in helping test whether this new vaccine could protect humans against the pandemic coronavirus.”

Sarah Gilbert, a vaccinology expert at the Jenner Institute, said: “The COVID-19 vaccine trial team have been working hard on assessing the safety and immunogenicity of ChAdOx1 nCoV-19, and preparing to assess vaccine efficacy. We have had a lot of interest already from people over the age of 55 years who were not eligible to take part in the phase I study, and we will now be able to include older age groups to continue the vaccine assessment. We will also be including more study sites, in different parts of the country.”

After originating in China last December, COVID-19, the disease caused by the coronavirus, has spread to at least 188 countries and regions, with Europe and the US currently the worst hit.

The pandemic has killed more than 333,400 people worldwide, with over 5.12 million confirmed cases, while recoveries exceeded 1.96 million, according to figures compiled by Johns Hopkins University of the US.