Pfizer Inc and Moderna Inc are testing their Covid-19 vaccines against the new fast-spreading version of the virus that has emerged in Britain, CNN reported.

Moderna expects immunity from its vaccine to protect against the variants and is performing more tests in the coming weeks to confirm, the company said in a statement to CNN.

Pfizer said it is “generating data” on how well blood samples from people immunised with its vaccine “may be able to neutralise the new strain from the UK,” according to the report.

Pfizer and Moderna did not immediately respond to Reuters' requests for comment.