Their findings were published in the New England Journal of Medicine.
Forty-five healthy adults ages 18 to 55 were part of Phase 1. Researchers tested low, medium and high doses of the vaccine. Each patient received two shots 28 days apart.
The results: Every patient's immune system produced neutralizing antibodies to fight COVID-19.
There were some side effects. Participants reported fatigue, headache, chills, fever and pain at the injection site. Researchers found a mid-level dose was most effective and less prone to side effects.
What happens now?
Moderna will launch the next phase of testing on July 27. The trial will expand to 30,000 participants. Half will receive the vaccine. The other half will receive a placebo.
Researchers want a diverse -- more at-risk -- group of participants including older adults, minorities and those with underlying health conditions. This will happen in 87 different places across the country including here in Houston.
"We're looking for volunteers," said Dr. Vicki Miller with Texas Center for Drug Development.
DM Clinical and the Texas Center for Drug Development are working with Moderna on this phase of the trial.
"We need to show this vaccine is safe for all populations," said Miler.
Click here for more information on how to sign up. If you qualify, you could be paid for your time and participation.