Johnson & Johnson has started a new late stage trial to begin testing a two-dose regimen of its experimental COVID-19 vaccine. It will study potential benefits of a second dose.
The drug maker plans to have up to 30,000 participants for the study. A one-dose trial study had around 60,000 people.
Last week, drugmakers Pfizer and Bio-N-Tech said its potential vaccine showed more than 90 percent effective rate.