A drug to treat or even cure COVID-19 may be out there - already in use for other illnesses. 

But the problem is which one would work. 

This is one challenge being tackled by researchers in a federal laboratory in Brazil, CNPEM, led by medical doctor and molecular biologist Eduardo Pagani. 

CGTN correspondent in Brazil Paulo Cabral spoke to Dr. Pagani to learn more about his team's research.