Shares of the New Brunswick, N.J., health-care giant closed little changed at $145.24.
An independent committee investigated the case of a man in the trial who suffered a stroke and concluded it was not related to the vaccine, the Washington Post reported. The paper cited two people familiar with the trial who spoke on condition of anonymity.
The Johnson & Johnson trial was paused on Oct. 12 after the man who received a vaccination suffered a stroke.
To conclude it was not related to the shot, investigators looked at the medical details of the event and examined a safety database of 100,000 people who have received vaccines that use the same underlying technology, the Washington Post reported.
The company is testing the only vaccine that aims to protect people with a single shot; other prospective vaccines require a return visit and second shot three to four weeks after the first to trigger a protective immune response.
The J&J effort is part of the U.S. government's Operation Warp Speed effort to develop an effective vaccine for covid-19 and includes some 60,000 volunteers.
It was the second study in as many months to pause its dosing, following a similar decision by AstraZeneca in September.
AstraZeneca shares were little changed at $52.