Johnson & Johnson has temporarily paused its clinical trials for a potential novel coronavirus vaccine after an “unexplained illness” in a study participant, the company said Monday.
In a statement posted to its website, the company said the person’s illness is being reviewed and evaluated by the independent Data Safety Monitoring Board along with the company’s own physicians.
The company assured that such “serious adverse events” are not uncommon in clinical trials. It’s also not clear if the illness came from the vaccine candidate itself or from a placebo.
“Adverse events — illnesses, accidents, etc. — even those that are serious, are an expected part of any clinical study, especially large studies,” the company’s statement reads.
The news comes just over a month after AstraZeneca halted its own trial for a vaccine being developed with Oxford University after a “potentially unexplained illness” in the United Kingdom. The trial resumed six days later.
Johnson & Johnson’s Phase 3 COVID-19 vaccine trials, which began in late September, are one of the largest in the world so far. The company is testing the shot in 60,000 volunteers in the U.S., South Africa, Argentina, Brazil, Chile, Colombia, Mexico and Peru.
The potential vaccine, which is being developed by the company’s subsidiary Janssen in Belgium, is based on vector technology, the same used by AstraZeneca.
An early-to-mid stage clinical trial found the vaccine candidate produced a strong immune response against SARS-CoV-2, though it was unclear if older patients saw a similar result. The findings were published in late September.
No vaccine has completed Phase 3 trials yet anywhere in the world.
New vaccines or drugs go through multiple stages of trials on humans, looking first to see if they are safe and cause no serious adverse reactions. Each phase adds more people, with usually fewer than a dozen to start, rising to tens of thousands by Phase 3.
Johnson & Johnson has not yet applied for Canadian approval. AstraZeneca was the first company to do so, submitting its application its first scientific results on Oct. 2. Pfizer followed on Friday.
In the last two months, Public Services and Procurement Canada has signed deals with the makers of six COVID-19 vaccines, including AstraZeneca, that will see Canada spend more than $1 billion to get guaranteed access to between 20 million and 76 million doses of each one if they are approved.
The U.S., which has signed off on and championed Johnson & Johnson and other private companies’ vaccine efforts, is pushing to have a worthy candidate approved before the end of the year.
—With files from the Associated Press