The Oxford-AstraZeneca vaccine can be stored at conventional refrigerator temperatures, which makes it much simpler to dispense and is also cheaper than its main competitors.

Of 196 COVID-19 cases so far in its huge USA study, 185 were trial participants who received the placebo and 11 who got the real vaccine. All of those cases occurred in the placebo arm.

Moderna shares were up 6.7% at $138.58 in USA pre-market trade, a record high and a rise of more than 600% this year.

The results have arrived as new infections and COVID-19 hospitalisations are reaching record levels across the United States. A similar vaccine from Pfizer Inc. and BioNTech SE was submitted to USA regulators earlier this month and is scheduled to be reviewed ahead of Moderna's shot.

Moderna created its shots with the U.S. National Institutes of Health and already had a hint they were working, but said it got the final needed results over the weekend that suggest the vaccine is more than 94% effective.

The FDA, in response to the development, has told Moderna it should expect a meeting of the Vaccines and Related Biological Products Advisory Committee (VRBPAC) under its Center for Biologics Evaluation and Research (CBER).

"With a wide range of vaccine candidates in our portfolio, we stand ready to deploy a vaccine should they receive approval from our medicines regulator, starting with those who will benefit most". Once authorities sign off, the company will move quickly to distribute the shots, part of a vast vaccination effort that will unfold as hospitals in the US strain under a surge in infections. That vaccine could be approved and shipped within days, with Moderna's following one week behind that, Azar said.

"I allowed myself to cry for the first time", he said.

The UK has now secured over seven million doses of Moderna mRNA-1273.

The new analysis showed the vaccine worked consistently well in older and younger adults, as well as minorities, the company said.

As more vaccine gradually becomes available in coming months, other essential workers and people at highest risk from the coronavirus would get in line.

There was also one COVID-19 death in the placebo group. The only noteworthy side effects according to their data were headaches and fatigue, which only about 2% of participants reported.

And this week, a different panel of USA experts, established by the Centers for Disease Control and Prevention, will meet to decide how those initial supplies will be given out.

The full data from the Oxford-AstraZeneca trial is expected to be published soon and may answer some questions about the vaccine. They will meet on December 10 to review Pfizer's data.

The Moderna vaccine uses the novel messenger RNA (mRNA) technology to develop a vaccine that trains the body genetically to develop the required proteins to simulate a virus by itself and develop the necessary protections.

The UK medicines regulator is now assessing two vaccines - one developed by Pfizer and BioNTech, the other by Oxford University and AstraZeneca - to see if they are safe and effective. Moderna, which has co-developed the mRNA candidate with the National Institutes of Health, has already reached agreements to supply 100 million doses to the US and 80 million to the European Union, among others.