The World Health Organization's SOLIDARITY Trial — which will examine potential treatment options for Covid-19 — plans to enroll its first patients this week, WHO chief scientist Dr. Soumya Swaminathan said during a call with reporters today.

WHO announced last week that it had organized the trial to test coronavirus treatment approaches across several countries and compare data to find which treatments may be most effective. When the announcement was made, WHO noted that many countries agreed to join the trial, including Argentina, Bahrain, Canada, France, Iran, Norway, South Africa, Spain, Switzerland and Thailand.

“Randomized clinical trials normally take a lot of time to set up and get running, but you can see that the team has been able to put together this trial," Swaminathan said.

"Hopefully we’ll start enrolling in the first few countries this week," Swaminathan added. "We should be able to enroll thousands of patients in a matter of weeks or months — we can’t exactly predict right now."

The number of patients enrolled will depend on the course of the coronavirus pandemic, said Dr. Ana Maria Henao-Restrepo, a medical officer at WHO's Department of Immunization Vaccines and Biologicals.

“Nobody knows how many cases we are going to have and whether or not they are going to occur at the hospital where we are setting the trial," Henao-Restrepo said during the call.

In a separate media briefing on Monday, WHO Director-General Tedros Adhanom Ghebreyesus said that "small, observational and non-randomized studies will not give us the answers we need" when it comes to identifying effective coronavirus treatments.