As the U.S. enforces new restrictions to stop the omicron COVID-19 variant, pharmaceutical companies are also doing their part to fight the newest strain of the coronavirus.

Pfizer and BioNTech confirm they are taking swift action against the newest variant omicron.

Pfizer is testing the new strain on people who are fully vaccinated and people who have received a booster to see how well their vaccine is fairing against omicron.

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CEO Albert Bourla says they don't know the answer yet, but if they learn the vaccine isn't very protective against omicron, they already began working on a new vaccine on Friday that will be ready in 100 days.

This is something the company has already done for the delta and beta variants, but because the original vaccine remained highly effective against those strains, it never needed to use the new vaccine templates.

The company also expects Paxlovid, its COVID-19 treatment pill, to be effective against omicron. The CEO said it was designed with mutations in mind.

Moderna says the new variant represents a potential risk for both natural immunity and immunity gained from the vaccine.

Johnson & Johnson confirms it’s been closely monitoring newly emerging COVID-19 variants throughout the pandemic and evaluating the effectiveness of its COVID-19 vaccine against variants, including omicron.

The company announced it is also working on developing a new vaccine against omicron that will progress into clinical studies if needed, but did not provide a timeline.