Johnson & Johnson announced it has paused its coronavirus vaccine trials on Monday following an “unexplained illness” among one of its participants.
Johnson & Johnson stressed that adverse events during trials are expected, and a pause gives researchers an opportunity to review all of the medical information before moving forward with the trial. Johnson & Johnson added that it’s not always immediately known if the affected person received a placebo or a study treatment.
Among the trials paused was Johnson & Johnson’s multi-country “ENSEMBLE” vaccine, which entered Phase 3 testing in September. Johnson & Johnson said last month that its goal was to seek an emergency use authorization approval in early 2021.
The FDA noted that a vaccine candidate must be at least 50% effective to receive emergency use authorization. Vaccine candidates should include a median follow-up duration of at least two months after completion of the full vaccination regimen to help provide adequate information to assess a vaccine’s risk-benefit.
According to the FDA, a typical Phase 3 trial would take one to three years.
“NIH is committed to supporting several Phase 3 vaccine trials to increase the odds that one or more will be effective in preventing COVID-19 and put us on the road to recovery from this devastating pandemic,” said NIH Director Francis S. Collins, M.D., Ph.D. “We also know that preventing this disease could require multiple vaccines and we’re investing in those that we believe have the greatest potential for success.”