Moderna's Covid vaccine, which has shown 94 per cent efficacy, "remains stable at 2 to 8 degrees C (36 to 46 degrees F), the temperature of a standard home or medical refrigerator, for 30 days, the company said on Monday, sending waves of relief through the medical community.
A Pfizer vaccine breakthrough a week ago came with a challenging cold chain component for storage and transportation.
Anthont Fauci, America's top infectious diseases expert, called the Moderna results "striking". Fauci said the US is well on course to begin vaccinating its most vulnerable population by December.
At lower temperatures of -20 degrees C (-4 degrees F), the Moderna vaccine remains stable for up to six months, the company reported.
Once the vaccine is taken out of a refrigerator for administration, "it can be kept at room temperature conditions for up to 12 hours".
"We believe that our investments in mRNA delivery technology and manufacturing process development will allow us to store and ship our Covid-19 vaccine candidate at temperatures commonly found in readily available pharmaceutical freezers and refrigerators," said Juan Andres, Chief Technical Operations and Quality Officer at Moderna.
Moderna's vaccine, created in collaboration with the National Institutes of Health, has 30,000 volunteers in its fold. The population received either the real vaccine or a dummy shot.
The independent monitoring board, which reports on safety data found that among 95 infections recorded, 90 came from the placebo group and only five from the vaccine group, "resulting in a point estimate of vaccine efficacy of 94.5 per cent".
Another bright spot: All 11 "severe cases" occurred in the placebo group and none in the mRNA-1273 vaccinated group.
Pfizer and BioNTech had announced 90 per cent efficacy of its vaccine candidate exactly a week ago. Taken together, these two vaccines are firmly on course to seek emergency use authorisation from the US Food and Drug administration if results hold out in the final data crunch due soon.
Both Moderna and Pfizer-BioNTech use the 'mRNA' technology which means the vaccine is not embedded with the virus itself and therefore no risk of catching Covid-19 from the shot itself.
The vaccine is infused with a piece of genetic code that trains our immune system to recognize the spike protein on the surface of the virus - a lethal signature of the coronavirus.
