The US has added a second COVID-19 vaccine to its arsenal, boosting efforts to beat back an outbreak so dire that the nation is regularly recording more than 3,000 deaths a day.
Much-needed doses are set to arrive Monday after the Food and Drug Administration (FDA) authorised an emergency rollout of the vaccine developed by Moderna Inc. and the National Institutes of Health (NIH).
The move marks the world's first authorisation for Moderna's shots. The vaccine is very similar to one from Pfizer Inc. and Germany's BioNTech that's now being dispensed to millions of health care workers and nursing home residents as the biggest vaccination drive in US history starts to ramp up.
Earlier, US Vice President Mike Pence and other top officials and politicians received shots of the Pfizer vaccine in a live television event.
The FDA made its announcement on Twitter, following the recommendation of its Vaccines and Related Biological Products Advisory Committee on Thursday.
"The emergency use authorisation allows the vaccine to be distributed in the U.S for use in individuals 18 years and older," the FDA tweeted.
The two vaccines work "better than we almost dared to hope," NIH Director Dr Francis Collins told The Associated Press. "Science is working here, science has done something amazing."
Early results of large, still unfinished studies show both vaccines appear safe and strongly protective although Moderna's is easier to handle since it doesn't need to be stored at ultra-frozen temperatures.
A second vaccine represents a ray of hope amid despair as the virus continues to spread unabated even before holiday gatherings that are certain to further fuel the outbreak.
The scourge has claimed more than 312,000 American lives and killed 1.7 million people worldwide. New cases in the US are running at more than 216,000 per day on average.
Deaths per day have hit all-time highs, eclipsing 3600 on Wednesday. (Associated Press)