Philippine President Rodrigo Duterte said he will not allow students to go back to school until a coronavirus vaccine is available, even as some countries resume in-person classes, AFP reports.

Children were due to return to school at the end of August after classes for more than 25 million primary and secondary students were shut down in March as the contagion took off in the Philippines.

But in a speech aired late Monday, Duterte said the risk was too great, even if it held students back academically.

“Unless I am sure that they are really safe, it's useless to be talking about opening of classes,” the president said.

“For me, vaccine first. If the vaccine is already there, then it's okay,” he added. “If no one graduates, then so be it.” Though researchers have launched an unprecedented global effort to quickly develop a vaccine, it is not clear when a viable candidate will be proven and distributed on a large scale.