The World Health Organization's chief scientist said Monday that she was encouraged by early results suggesting Moderna's vaccine was nearly 95% effective, but that questions remain.
Of course, we need to wait and see what the final efficacy and the safety profile of this vaccine will be when the whole data is analyzed after they reach their primary endpoint," Dr. Soumya Swaminathan said.
Moderna is the second vaccine in the US to have a stunningly high success rate. BioNTech and Pfizer announced last week that their jointly developed vaccine was more than 90% effective.
One of the major differences between the two vaccines is the temperature at which they must be stored, which will have a big impact on their distribution. Pfizer's vaccine has to be kept at minus 75 degrees Celsius — or about minus 103 degrees Fahrenheit. Moderna's vaccine can be kept at minus 20 degrees Celsius, which is about minus 4 degrees Fahrenheit.