Swiss researchers have suspended the testing of one of the leading Ebola vaccine candidates after some volunteers reported unexpected side effects. In a statement issued today, the University of Geneva Hospital said the trial—which had vaccinated 59 people since November—had been suspended "as a precautionary measure." Researchers reported four cases of mild joint pain in the hands and feet in people who got the shot 10 to 15 days earlier; before the joint pain kicked in, a handful of subjects experienced mild fever. "They are all fine and being monitored regularly by the medical team leading the study," the hospital says in a statement cited by Reuters.
"The Geneva team has decided to allow time to understand what is happening," the statement adds. A WHO vaccine expert tells Reuters that "it's not a setback, not at all." Officials will stop giving the vaccine next week to get more data and liaise with others who are testing the vaccine in the US, Canada, Germany, and Gabon. "These centers have not observed symptoms of inflammation in their volunteers to date," the hospital's statement adds, per Reuters. The trial is scheduled to resume Jan. 5 in Geneva after the hospital is able to determine if the joint pain symptoms were "benign and temporary." The vaccine was developed by the Canadian government and is licensed to two US companies, NewLink and Merck.