BioNTech's CEO says he is confident the vaccine will work against a new strain of COVID-19.

The virus variant has been found in the United Kingdom and other countries.

CEO Uğur Şahin says he has confidence in the Pfizer vaccine because "the proteins on the variant are 99% the same as the prevailing strains."

He says further studies are needed to be completely sure.

Moderna says it believes its vaccine would protect against the mutation but they are also doing additional tests to confirm that.

COVID-19 has mutated before and both companies say their vaccines worked against those variations.