Johnson & Johnson's COVID-19 vaccine trial has been paused while the company investigates whether a study participant's “unexplained illness” is related to the vaccine shot.
The company said in a statement on Monday evening that illnesses, accidents and other so-called adverse events “are an expected part of any clinical study, especially large studies,” but added that the company will set up a safety monitoring panel to determine the participant’s cause of illness. The company has said it will begin its investigation by first determining if the participant received the vaccine or a placebo. The company declined to reveal further details about the illness, citing the participant's privacy.
Temporary pauses in large medical studies are relatively common, however, the coronavirus vaccine has raised the stakes in these kinds of complications. Companies are required to investigate any serious or unexpected reaction that occurs during drug testing. Given that such tests are done on tens of thousands of people, some medical complications are expected.
Johnson & Johnson was aiming to enrol 60,000 volunteers to determine if its single-dose approach is safe and guarantees protection against coronavirus. Other COVID-19 vaccine candidates that are being developed in the US require two shots.
The final stage of testing of the COVID-19 vaccine candidate being developed by AstraZeneca and Oxford University has been paused in the US, as officials examine whether an illness in its trial poses a safety risk. That trial was stopped when a woman developed severe neurological symptoms consistent with transverse myelitis, a rare inflammation of the spinal cord, AstraZeneca said. However, the vaccine’s testing has resumed in other countries.