Moderna submitted its coronavirus vaccine for regulatory approval Monday, the Food and Drug Administration confirmed — the second leading drug to pass the milestone this month.
The Massachusetts biotech firm asked the FDA for emergency use authorization after completing its Phase 3 trial, finding the vaccine was 94.1 percent effective against Covid-19.
Moreover, Moderna said the vaccine was 100 percent effective at preventing severe cases of the disease.
These results were the same across all age, race and gender categories, the company said in a statement. There have been no serious safety concerns so far, it added, with the most common side effects being fatigue, headaches, and muscle and joint pain.
The FDA said its Vaccines and Related Biological Products Advisory Committee will convene Dec. 17 to discuss its submission. That is a week after the FDA is expected to discuss another candidate, developed by the U.S. pharma giant Pfizer and its German partner BioNTech, which has also applied for regulatory approval having observed a similar level of efficacy.
Both the Moderna and Pfizer-BioNTech drugs involve inserting special code called mRNA into the body, tricking it into developing an immune response. No mRNA-based drug has ever won approval before.
Hajo Zeeb, a professor at Germany's Leibniz Institute for Prevention Research and Epidemiology, said it's hugely encouraging that two separate studies both found similar high levels of success.
"I would be surprised if something different came out in the FDA process, and I think these are highly likely to be approved," he said.
Though optimistic, Zeeb cautioned that the exact percentages may change once hundreds of millions, rather than tens of thousands, of people start taking the vaccine.
"These are still small numbers overall," he said of the trial's sample size, "but the reduction in severe cases is exactly what we want to see. If it's just a mild virus, we can live with that."
Moderna received more than $1 billion in U.S. federal government funding to develop and produce its candidate, and another $1.5 billion to supply it to the American public.
Its trial involved 30,000 people, half of whom were given the vaccine candidate and other half a placebo. Of this group, the scientists recorded 196 cases of Covid-19, only 11 of whom were from the group that had been given the vaccine. There were 30 cases of serious illness — all of them in the placebo group.
So of the 15,000 people given the vaccine, not one became seriously ill with Covid-19 during the trial period, the company said.
Last week, AstraZeneca and Oxford University championed their own promising results, only to later admit there had been a technical error during its trial and that it was planning on running some additional tests. Like the others, there has been no suggestion its vaccine is unsafe.
Download the NBC News app for the latest news on the coronavirus
While recent developments have been met with widespread optimism among scientists and stock markets, experts are also urging caution until more data is released beyond the various companies' triumphant non-peer-reviewed press releases. These vaccine trials are primarily geared toward preventing symptomatic disease, but questions remain about how effective they are at stopping transmission, too.
President-elect Joe Biden has also warned that vaccines, which will take time to approve and roll out, may do nothing to soften the tough winter facing the U.S., Europe and elsewhere.
Coronavirus cases continue to surge, with more than 267,000 Americans dead and fears that Thanksgiving might bring yet more fatalities. Europe was gripped by a similar wave until widespread lockdowns began to turn the tide. More than 1.4. million have been killed globally.
Even if these drugs get regulatory approval, rolling out the shots to billions of people around the world will involve a byzantine supply-chain challenge at a scale never attempted before.