The study of Johnson & Johnson’s Covid-19 vaccine has been paused due to an unexplained illness in a study participant.
A document was sent to outside researchers running the 60,000-patient clinical trial stating that a “pausing rule” has been met, that the online system used to enroll patients in the study has been closed. The data and safety monitoring board — an independent committee that watches over the safety of patients in the clinical trial — would be convened. The company declined to provide further details.
“We must respect this participant’s privacy. We’re also learning more about this participant’s illness, and it’s important to have all the facts before we share additional information,” the company said in a statement.
Johnson & Johnson emphasized that adverse events, illnesses, accidents, and other bad medical outcomes, are expected during clinical, and a pause gives researchers an opportunity to review all of the medical information before moving forward with the trial. Johnson & Johnson also said that it’s not always immediately known if the affected person received a placebo or a study treatment.
Given the size of the trial, it’s not surprising that study pauses could occur, and another could happen if this one resolves, a source said.
“If we do a study of 60,000 people, that is a small village,” the source said. “In a small village, there are a lot of medical events that happen.”
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.”