The World Health Organization has so far listed 202 COVID-19 vaccine candidates, 47 of which are currently undergoing clinical human trials.
At least ten are in the third and final phase of testing, and those include vaccines by U.S. pharmaceutical giants Moderna and Pfizer.
On Monday, Moderna said preliminary data show its vaccine to be 94.5 percent effective.
The announcement came a week after Pfizer said its vaccine had an efficacy rate of more than 90 percent.
A key difference between the two vaccines, however, is the temperature at which they need to be stored.
Pfizer's vaccine needs to be kept at minus 70 degrees Celsius, which would require special freezers.
On the other hand, Moderna's vaccine can be kept at a normal refrigerator temperature of two to eight degrees Celsius for up to 30 days.
For longer periods of up to six months, it should be stored at minus 20 degrees, a temperature more feasible than the Pfizer vaccine for distribution.
Both vaccines require two doses seperated by several weeks, and they use a new vaccine technology.
Unlike conventional vaccines, which involve injecting an inert or weakened version of a virus into the body, the mRNA doesn't require injecting a virus.
These vaccines instruct the body's cells to create viral proteins, which the body detects, triggering an immune response.
The CEO of Pfizer told reporters on Tuesday that the company is preparing to apply for emergency authorization from the U.S. Food and Drug Administration.
If that's received, Pfizer's will be the first-ever authorized vaccine using the mRNA method.
U.S. health officials are feeling confident that these first candidates are on the right track.
"I'm confident that when the FDA approves those vaccines and so far there's been two that have been really quite effective, efficacious, and there will be more that I would, without hesitation, take the vaccine"
As for other countries, Russia recently announced that its vaccine is 92 percent effective, and China's vaccine is also in the final stage of testing.
Min Suk-hyen, Arirang News.