Covid vaccine development in Leiden paused over sick test subject

American company Johnson & Johnson hit another setback in the development of a vaccine against Covid-19. The company, which also includes Janssen in Leiden, temporarily halted the development due to a sick test subject, Johnson & Johnson said on its website.

What exactly is going on is not yet clear. The pharmaceutical only said that the test subject became ill unexpectedly, and that it is investigating. Johnson & Johnson stressed that negative effects like illness are not uncommon in medical trials on this scale.

Until more is known, no new subjects can be enrolled in the trials, and the current participants will not receive any further doses of the vaccine. About 60 thousand people worldwide are participating in this clinical trial.

The company also asked an independent safety committee to investigate.

Another Covid-19 vaccine, being developed by AstraZeneca, was also previously paused after a trial participant fell ill. This participant got a rare spinal cord infection.