Friday, the World Health Organization (WHO) Europe director Hans Kluge warned that the vaccine rollout across the region was still "too slow."

He told AFP "The pandemic will be over once we reach 70 percent minimum coverage in vaccination."

Kluge expressed his concern about the fast transmission of mutated COVID-19 strains, such as the British and Indian strains.

"We know for example that the B.1617 (Indian variant) is more transmissible than the B.117 (British variant), which already was more transmissible than the previous strain," Kluge said.