The World Health Organization said on Tuesday that some treatments appear to be limiting the severity or length of the Covid-19 respiratory disease and that it was is focusing on learning more about four or five of the most promising ones.

“We do have some treatments that seem to be, in very early studies, limiting the severity or the length of the illness, but we do not have anything that can kill or stop the virus,” spokeswoman Margaret Harris told a virtual briefing, referring to the body’s “solidarity trial” of drugs against the disease.

“We do have potentially positive data coming out but we need to see more data to be 100% confident that we can say this treatment over that one,” she added.