Johnson & Johnson’s single-dose vaccine enters phase 3 trials

This September 2020 photo provided by Johnson & Johnson shows a single-dose COVID-19 vaccine being developed by the company.  Cheryl Gerber/Courtesy of Johnson & Johnson/AP

Johnson & Johnson’s Covid-19 vaccine candidate begins phase 3 trials in the United States on Wednesday. Trials for the single-dose vaccine, which uses a human adenovirus, will include up to 60,000 adult participants at nearly 215 sites in the US and internationally. 

 The vaccine candidate was developed by Janssen Pharmaceutical Companies, a subsidiary of Johnson & Johnson. Phase 3 trials will begin immediately, with the first participants receiving doses Wednesday, Johnson & Johnson Chief Scientific Officer Dr. Paul Stoffels said on a call with reporters Tuesday.

Initial findings from the vaccine’s phase 1/2 trials in the US and Belgium suggest the vaccine provokes an immune response and is safe enough to move into large-scale trials. 

Phase 3 trials will examine the safety and effectiveness of a single dose against a placebo to prevent symptomatic Covid-19. The fact that the trial will examine the efficacy of a single dose of the vaccine, instead of two doses, should expedite results, said Stoffels.

Trials will run in Argentina, Brazil, Chile, Colombia, Mexico, Peru, South Africa and the United States. Johnson & Johnson intends to run a separate phase 3 trial in collaboration with the UK government to examine the effectiveness of two doses

If the vaccine is proven safe and effective, Johnson & Johnson said it expects the first doses to be available for emergency use authorization from the US Food and Drug Administration by early 2021. 

Where things stand: Moderna, Pfizer/BioNTech and AstraZeneca also have Covid-19 vaccine candidates in Phase 3 trials in the United States, although AstraZeneca’s trial is currently paused.

Johnson & Johnson’s phase 3 trial is being conducted in collaboration with Operation Warp Speed, the federal government’s coronavirus vaccine effort.

Dr. Gupta discusses Johnson & Johnson’s vaccine: