Moderna vaccine a 'crucial step' in virus fight

The US added a second COVID-19 vaccine to its arsenal Friday, 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 authorized an emergency rollout of the vaccine developed by Moderna Inc. and the National Institutes of Health.

The move marks the world's first authorization 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 U.S. history starts to ramp up.

Both vaccines carry "a remote chance" of causing a severe allergic reaction.

Moderna's study turned up none of these, though a handful were reported in Britain as the Pfizer-BioNTech vaccinations got underway and the FDA is looking into five in the US, including a severe reaction in Alaska.

The vaccines' ingredients aren't identical.

Still, after any COVID-19 vaccination, people should stick around for 15 minutes – or 30 minutes if they have a history of severe allergies – so if they do have a reaction, it can be treated immediately.