The chief executive of BioNTech says the German pharmaceutical company is confident that its coronavirus vaccine works against the UK variant, but further studies are need to be completely sure.

Ugur Sahin said Tuesday that “we don’t know at the moment if our vaccine is also able to provide protection against this new variant,” but because the proteins on the variant are 99% the same as the prevailing strains, BioNTech has “scientific confidence” in the vaccine.

Sahin said BioNTech is currently conducting further studies and hopes to have certainty within the coming weeks.

“The likelihood that our vaccine works ... is relatively high,” he said.

BioNTech’s vaccine, developed together with U.S. pharmaceutical company Pfizer, is authorized for use in more than 45 countries including Britain, the United States and the European Union.