For the second time in as many weeks, there is promising news from the race for a COVID-19 vaccine as infections surge across the United States and Europe.

US biotech firm Moderna Inc on Monday said preliminary data from a continuing phase three study of its experimental COVID-19 vaccine showed it to be 94.5 percent effective.

This is a pivotal moment in the development of our COVID-19 vaccine candidate,” said Moderna’s CEO Stephane Bancel in a statement. “This positive interim analysis from our Phase 3 study has given us the first clinical validation that our vaccine can prevent COVID-19 disease, including severe disease.”

The news follows on from last week’s announcement from US drug giant Pfizer that phase three trial results for the COVID-19 vaccine it is developing with Germany’s BioNTech showed it to be more than 90 percent effective.

The results of both trials place Moderna and Pfizer on track to seek authorisation from the US Food and Drug Administration in the coming weeks for emergency use of their vaccines.

If they get the green light from the FDA, supplies of both vaccines would be limited and rationed before the end of the year. Both vaccines require people to get two shots, several weeks apart.

Moderna expects to have about 20 million doses, earmarked for the US by the end of 2020. Pfizer and BioNTech expect to have about 50 million doses globally by the yearend.

US Secretary of Health and Human Services Alex Azhar responded to the Moderna news on Twitter, writing: “This news is another stunning result of President Trump’s leadership and his unwavering support for #OperationWarpSpeed, an incredible tribute to American scientists and innovators, and one more reminder that there is light at the end of the tunnel.”

Pfizer’s CEO, Albert Bouria, said on Twitter that he is “thrilled” by Moderna’s trial result, adding: “Our companies share a common goal – defeating this dreaded disease – and today we congratulate everyone at Moderna and share in the joy of their encouraging results.”