Scientists have hailed the "tremendously exciting" news that a US coronavirus vaccine may prevent 94.5% of people from getting Covid-19.
Interim data from the US firm Moderna suggests its vaccine is highly effective in preventing people getting ill and also works across all age groups, including the elderly.
Moderna reached a $1.5billion deal with the US government for 100 million doses of their vaccine in August.
But scientists said the news bodes well for other Covid-19 vaccines, with the one for Oxford University and UK pharmaceutical giant AstraZeneca due to report in the coming days or weeks.
Moderna intends to submit an application for an Emergency Use Authorisation with the US Food and Drug Administration shortly and will submit further data on the vaccine's effectiveness and safety.
Best of all, the vaccine is more stable than expected at temperatures that ordinary refrigerators can provide and can be distributed using existing cold-chain shipping and storage infrastructure.
Moderna's vaccine is stable for up to six months at a temperature of minus 20 degrees Celsius (-4 F), about home freezer levels, when shipped and stored.
The company said it expects the vaccine to be stable when kept at standard refrigerator temperatures of 2 to 8 degrees Celsius for 30 days, up from an initial projection of 7 days.
The vaccine will be distributed in 10-dose vials and can be kept at room temperature for up to 12 hours after thawing.
By comparison, Pfizer's vaccine can be transported and stored for up to 6 months at minus 70 degrees Celsius (-94 F).
It can be stored at standard refrigerator temperatures for up to five days.
Moderna's vaccine will be distributed by the U.S. government's Operation Warp Speed program. U.S. health officials have said that at first they are most likely to distribute vaccines to healthcare workers, people who are in nursing homes, first responders and those with health conditions who are high-risk.
