AstraZeneca’s pause of an experimental vaccine for coronavirus after the illness of a participant is a “wake-up call” but shouldn’t discourage researchers, WHO chief scientist Soumya Swaminathan said.

“This is a wake-up call to recognize that there are ups and downs in clinical development and that we have to be prepared. We do not have to be discouraged. These things happen,” she added.

“It’s a race against this virus, and it’s a race to save lives. It’s not a race between companies, and it’s not a race between countries,” said WHO’s head of emergencies Mike Ryan.