A Chinese experimental coronavirus vaccine being developed by the Institute of Medical Biology under the Chinese Academy of Medical Sciences was shown to be safe in an early stage clinical trial, researchers said.

In a Phase 1 trial of 191 healthy participants aged between 18 and 59, vaccination with the group’s experimental shot showed no severe adverse reactions, its researchers said in a paper posted on medRxiv preprint server ahead of peer review.

The most common adverse reactions reported by the trial participants were mild pain, slight fatigue and redness, itching and swelling at the injection site, Reuters reported.