>>If you look at the world distribution of virus cases, there are very few in Africa, where malaria drugs have been used for many years.<<
I thought that too, at first, but apparently chloroquine isn’t effective against malaria any longer as the disease has mutated since it was developed.
It wouldn’t hurt, though to find out whether it’s still generally taken, especially in Africa and in India. India, especially, had a very slow start to their Wuhan Flu cases, possibly due to lack of testing?
A second, possibly a third agent is often added to a quinine derivative drug for Malaria. The protozoan mutated and gained the ability to dodge the effect of hydroxychloroquine on it’s metabolic processes. The drug combination restores potency to shutting down the Malaria.