The UN health agency warned on Wednesday that it was "far too early" to say when the coronavirus or COVID-19 could end after a drop in new cases.
"I think it is far too early to predict the beginning, middle or end of this epidemic," said Michael Ryan, director of the WHO Health Emergency Program, at the agency's daily press conference.
WHO chief Tedros Adhanom Ghebreyesus said: "The number of newly reported cases from China has stabilized over the past week, but this must be interpreted with extreme caution.
"This outbreak could go in any direction," he added.
The virus has killed more than 1,100 people and infected over 44,600 since it was first discovered on December 31.
Ryan said WHO managed to locate transmission sources in almost all 441 cases of the virus outside of China, with eight exceptions.
"We have a good view of this virus globally," he said.
Tedros also praised Cambodia for agreeing to host the US cruise ship Westerdam, which was rejected in several Asian ports because of coronavirus concerns.
"This is an example of the international solidarity that we have always called for," he said.
"Outbreaks can cause the best and worst in people. The stigmatization of individuals or entire nations harms the response.
"Instead of channeling all of our energy against the outbreak, the stigma distracts our attention and distracts people from each other," he added.
Around 300 scientists and donors met in Geneva on Tuesday and Wednesday for the first WHO international conference on the virus.
Four possible vaccines against the virus were discussed and are funded through the Coalition for Innovations in Disease Prevention (CEPI).
"I think we will find a vaccine. It will take some time. A vaccine cannot be made overnight," Soumya Swaminathan, WHO chief scientist, told reporters.
"Four vaccines are now funded for the early stages, pre-clinical development," she said.
Swaminathan said the first vaccine that is expected to be tested on humans in April is a vaccine developed by US Moderna Therapeutics in collaboration with the US National Institutes of Health.