The experimental vaccine was given in three separate doses - 25 micrograms, 100 micrograms, and 250 micrograms - to 45 people (each dose for 15) at a gap of approximately 28 days.
Then, the participants were closely monitored to see how it worked.
Results show antibodies in all volunteers
Now, the early results revealed by Moderna show that the vaccine has produced detectable antibodies in all the volunteers, with dose-dependent increment in immunogenicity.
The company says that the participants who got the 25 micrograms shot generated antibodies at levels seen in blood samples of recovered COVID-19 patients, while the 100 micrograms group had antibodies that "significantly exceeded levels" seen in recovered cases.
Some volunteers produced neutralizing antibodies
While the data of the third 250 micrograms group was not available, the team did note that the vaccine candidate was able to produce neutralizing antibodies in at least eight of the participants (four each from 25 and 100 micrograms group).
Now, this is a great development, given that neutralizing antibodies play a major role in fighting off viruses like the novel coronavirus.
Antibody levels consistent with animal trials
Moderna also notes that the level of neutralizing antibodies generated from the vaccine in humans is consistent with those seen in animals.
The company had worked with the NIH to test the vaccine on mice, which were able to generate enough antibodies to fight off the novel coronavirus and prevent it from replicating in the lungs.
Here's what Moderna chief medical officer Dr. Tal Zaks said
"These interim Phase 1 data, while early, demonstrate that vaccination with mRNA-1273 elicits an immune response of the magnitude caused by natural infection starting with a dose as low as 25. These data substantiate our belief that mRNA-1273 has the potential to prevent COVID-19 disease."
More data still needed to confirm full efficacy
The results are promising but the team still needs more data, especially on the antibodies, to confirm mRNA-1273's efficacy/safety.