Johnson & Johnson is the world's largest health care company.
Business Insider reports that the company plans to start testing its coronavirus vaccine candidate in humans in July.
On Wednesday, Johnson & Johnson it will move up the timeline by about two months to start clinical trials.
It was previously aiming for trials in September.
1,045 healthy volunteers in the US and Belgium will join the study, which starts in July.
If the vaccine works, J&J has already pledged to distribute it at a nonprofit rate to help end the pandemic.