Moderna Inc became the second US pharmaceutical company to release data from a large study of its experimental vaccine, saying it was 94.5 percent effective against COVID-19.
It will seek emergency use authorisation from the US Food and Drug Administration once it has more safety data, expected later this month.
Its first analysis was based on 95 cases of COVID-19, 90 of which received a placebo with 5 receiving the vaccine.
There were 11 severe cases in the placebo group and none among those that got the vaccine.
The 95 cases included 15 adults aged 65 or over, and 20 participants from diverse communities including 12 people who identified as Hispanic, 4 Black Americans, 3 Asian Americans and 1 person who was multiracial.
The results come one week after Pfizer Inc and German partner BioNTech SE said their experimental vaccine was more than 90 percent effective based on initial data.
Moderna, which went public in 2018, has received nearly $1bn in research and development funding from the US government and has a deal worth $1.5bn to supply 100 million doses.
The US government has an option for another 400 million doses and Moderna also has supply deals with other countries.