The University of Oxford will begin testing the COVID-19 vaccine it developed with AstraZeneca on children, a potentially key step in ending the global pandemic.

The Oxford trial plans to enroll 300 children aged 6 to 17, the university said in a statement Saturday. The first vaccinations will take place this month, with as many as 240 kids receiving the coronavirus vaccine and the remainder a meningitis shot, which should produce similar side effects. A larger trial involving thousands of children is expected to be conducted by Astra in the U.S. later.

The phase II study will take place at three cities across the U.K. – London, Southampton and Bristol – and assess the safety and immune responses in children. Investigators will test the shot on kids aged 12 to 17 first before moving to the younger age group, with initial data expected by summer, Andrew Pollard, lead investigator on the trial, said in a Bloomberg interview.

The study will look at two dosing regimens one month and three months apart, Pollard said.

Child trials started in earnest at the end of last year after the safety and efficacy of the frontrunner vaccines had been established in adults. Pfizer, which has an approved vaccine for people aged 16 and over, completed enrollment for its trial of 12-to-15-year-olds last month with more than 2,000 children tested. Moderna Inc. is also testing its shot on teenagers and Johnson & Johnson is expected to start child trials soon.

We planned to conduct child trials from the beginning "to make sure that we had the greatest opportunity for access across all ages" to the vaccine, said Pollard.

"I'm absolutely delighted that today we're launching the pediatric trials after this long road that we've been on," he added.

While most children have limited or no symptoms from COVID-19 and rarely become seriously ill, little is known about how much they might transmit the virus. Vaccinating young people could be key to halting the spread of the virus, helping to keep schools open and stopping older relatives and people in the community from falling sick.

As of Feb. 4, about 2.93 million children in the U.S. had tested positive for the coronavirus since the onset of the pandemic, according to the American Academy of Pediatrics.