Johnson & Johnson has temporarily paused all of its COVID-19 vaccine trials after a participant suffered an "unexplained illness."
The company said Monday night that the participant's illness is being reviewed and evaluated by an independent safety monitoring board, as well as its own physicians.
"Adverse events – illnesses, accidents, etc. - even those that are serious, are an expected part of any clinical study, especially large studies," the company said in a statement.
Last month, Johnson & Johnson said it aimed to enroll 60,000 volunteers to test its single-dose approach in the U.S. and seven other countries. Other COVID-19 vaccine candidates in the final stage of testing in the U.S. require two shots. The Johnson & Johnson trial is slated to be one of the largest coronavirus studies yet.
In early September, AstraZeneca paused the Phase 3 trial of its vaccine candidate after a patient reported a serious side effect. Testing of that vaccine, which was co-developed by Oxford University, has resumed in some countries but not in America. As of last week, AstraZeneca said it was still working with the U.S. Food and Drug Administration "to facilitate review of the information needed to make a decision regarding resumption of the US trial."
Monday's announcement by Johnson & Johnson means two of the four COVID-19 vaccine trials currently in Phase 3 in the U.S. are paused. The others currently in large-scale trials are Pfizer and Moderna.
Pfizer's CEO has said he expects data on whether the company’s vaccine candidate works to be ready in late October. Moderna's CEO said it expect to know by November if its vaccine works.
A Trump administration official leading the pandemic response said last week that the U.S. can expect delivery of a vaccine starting in January 2021, despite statements from the president that inoculations could begin this month.
