U.S. biotechnology firm Moderna Inc. said Wednesday that its COVID-19 vaccine is expected to be protective against variants of the novel coronavirus recently detected in Britain, based on data to date.

"We will be performing additional tests of the vaccine in the coming weeks to confirm this expectation," the Massachusetts-based company added in its statement.

It also said it has tested sera from animals and humans vaccinated with its COVID-19 vaccine against a number of previous variants of the virus that have emerged since the first outbreak of the pandemic, and found it to "remain equally effective."

A scientist works in the lab at Moderna in Cambridge, MA on Feb. 28, 2020. (The Boston Globe/Getty/Kyodo)

Moderna's two-dose vaccine was put into practical use in the United States on Monday, following the rollout of a vaccine manufactured by U.S. pharmaceutical giant Pfizer Inc. and its German partner BioNTech SE.

But the news has been overshadowed by concerns sparked about new strains of the virus reported in Britain.

Both the Moderna and Pfizer vaccines use a new technology known as messenger RNA, or mRNA.

While traditional vaccines put a weakened or inactivated germ into human bodies to trigger an immune response, mRNA vaccines give instructions for cells to make a harmless "spike protein" that resembles one found in the novel coronavirus.

The immune system then detects the protein and starts building an immune response and making antibodies to protect against future infection.

Canadian health authorities have also approved the use of Moderna's vaccine. The U.S. company, meanwhile, has an agreement with the Japanese government to supply the Asian country with enough vaccine doses for 25 million people.

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