Early stage trials of Johnson & Johnson's experimental coronavirus vaccine show it generated an immune response in nearly all volunteers, with minimal side-effects, after a single dose.
The company expects to report details of more advanced trials later this month and is hoping to apply for authorization from the US Food and Drug Administration soon after. Researchers who tested the vaccine in a combined Phase 1-2 trial -- mostly meant to show safety -- found either one or two doses of the vaccine generated both antibody and T-cell responses against the coronavirus. The trials were not designed to show whether the vaccine protected people against either infection or symptoms of coronavirus -- that's what the ongoing Phase 3 trials are designed to do. Writing in the New England Journal of Medicine, an international team of researchers who tested the vaccine in around 800 volunteers said the early stage trials showed it was safe and probably should work.
The researchers -- in the Netherlands, the United States and Belgium -- tested the vaccine in a group of people 65 and older and a group ages 18 to 55. Vaccination elicited neutralizing antibodies -- expected to stop the virus from infecting cells -- in 90% of all participants by the 29th day after the first dose of vaccine and in all of them by two months after the first dose. The levels of these antibodies stayed stable for at least 71 days, they reported.
"The Company anticipates announcing topline Phase 3 data for its single-dose Janssen COVID-19 vaccine candidate in late January 2021; however, as this trial is dependent on disease events, the timing is approximate," Johnson & Johnson said in a statement. But with the pandemic raging in the US and Europe, vaccine experts say, answers are coming quickly for vaccine trials.
"If the single-dose vaccine is shown to be safe and effective, the Company expects to submit an application for Emergency Use Authorization with the U.S. Food and Drug Administration shortly afterwards, with other regulatory applications around the world to be made subsequently," Johnson & Johnson added.