"The viral genome was mapped in early January and shared globally which enabled tests to be developed and vaccine research to start," Tedros said at a news conference at WHO headquarters in Geneva.

He said more than 70 countries have joined WHO's trial to accelerate research on effective treatments and "about 20 institutions and companies are racing to develop a vaccine."

Dr. Mike Ryan, the WHO's executive director for emergencies program, said one trial underway will look at prophylaxis in health-care workers to see if there's evidence of giving lower doses of drugs like hydroxychloroquine would reduce their risk of becoming infected while treating patients.

Tedros said the WHO will be announcing an initiative soon for the accelerated development and equitable distribution of vaccines.

"We will put together a mechanism and we will appoint senior people from the north and south that will work out the details of how they can accelerate production but at the same time how they can ensure equitable distribution," he said. "When a vaccine or a medicine is ready, we have to be able to deliver it to all over the world. There should not be a divide between the haves and the have-nots."

New York state last month began the first large-scale clinical trial looking at hydroxychloroquine as a possible treatment for the coronavirus after the Food and Drug Administration fast-tracked the approval process.

President Donald Trump has said chloroquine and hydroxychloroquine could be a "game-changer," even though the drugs have not been put through rigorous clinical trials to fight CV-19, which has infected more than 1 million people worldwide in a little over three months. Trump last month directed the FDA to examine whether the drugs can be used to prevent or treat the coronavirus.

Chloroquine has gained a lot of attention after a small study of 36 COVID-19 patients published March 17 in France found that most patients taking the drug cleared the coronavirus from their system a lot faster than the control group. Adding azithromycin, commonly known as a Z-Pak, to the mix "was significantly more efficient for virus elimination," the researchers said. A small study in China also found that combining chloroquine with azithromycin was "found to be more potent than chloroquine."