A mixed verdict so far, with skeptics, but also some hopeful assessments. What might the mechanism be by which it could work?
In the UK, Robin May, Professor of Infectious Disease at the University of Birmingham, explained that there is a scientific rationale for the use of hydroxychloroquine in the treatment of COVID-19, based on its mode of action in malaria.
In a statement through the Science Media Centre, he explained that, as chloroquine is a "weak base" and so helps to neutralise acids, it makes the environment "less suitable" for the malaria parasite to live in when it diffuses into red blood cells.
While the mode of action against COVID-19 is not established, Prof May said, he pointed out that many viruses enter host cells via endocytosis, as a result of which they are initially taken up into an intracellular 'compartment that is "typically fairly acidic”.
Chloroquine would alter the acidity of this compartment, which can interfere with the ability of viruses to escape into the host cell and start replicating.”
He continued: "Another possibility is that chloroquine may alter the ability of the virus to bind to the outside of a host cell in the first place,” adding that the drug "has subtle effects on a wide variety of immune cells…and it may be that one of these effects helps stimulate the body’s ability to fight off COVID-19.”
Crucially, the drug is also "cheap and relatively easy to manufacture" and so could easily be put into clinical trials and, eventually, treatment, May underlined.
(Thanks to Dr. David Ozonoff for the pointer.)
