Shares of the New Brunswick, N.J., health-care icon at last check were up 0.5% to $151.17.
The Phase III trial would enroll up to 60,000 healthy people ages 18 and older across nearly 180 locations in the U.S. and other countries, according to ClinicalTrials.gov, a U.S. government database of clinical trials, and CNBC.
“Our Phase 3 program is intended to be as robust as possible, could include up to 60,000 participants and will be conducted in places with high incidence rates,” J&J spokesman Jake Sargent said in a statement to CNBC.
“We are using epidemiology and modeling data to predict and plan where our studies should take place and expect that to be finalized soon.”
Participants will be randomly selected to receive a dose of the potential vaccine or a placebo.
The trial would be conducted in nearly 180 sites across the United States and other countries, including Brazil and Mexico.
Johnson & Johnson said it was using the same technologies it used to make its experimental Ebola vaccine, which was provided to people in the Democratic Republic of Congo in late 2019.
It involves combining genetic material from the coronavirus with a modified adenovirus that is known to cause common colds in humans.
More than 160 vaccines are under development worldwide, according to the World Health Organization.
Earlier this month, Johnson & Johnson said it reached an agreement with the U.S. government to provide 100 million doses of its potential coronavirus vaccine.
The provisional agreement would see the production and distribution of 100 million doses of the Janssen SARS-CoV-2 investigational vaccine, in exchange for a payment of around $1 billion