The available data are thin. The drugs work by decreasing the acidity in endosomes, compartments inside cells that they use to ingest outside material and that some viruses can coopt to enter a cell. But the main entryway for SARS-Cov-2 is a different one, using its so-called spike protein to attach to a receptor on the surface of human cells. Studies in cell culture have suggested chloroquines have some activity against SARS-CoV-2, but the doses needed are usually high—and could cause serious toxicities.
Encouraging cell study results with chloroquines against two other viral diseases, dengue and chikungunya, didn’t pan out in people in randomized clinical trials. And non-human primates infected with chikungunya did worse when given chloroquine. “Researchers have tried this drug on virus after virus, and it never works out in humans. The dose needed is just too high,” says Susanne Herold, an expert on pulmonary infections at the University of Giessen, Germany.
Results from COVID-19 patients are murky. Chinese researchers who report treating more than 100 patients with chloroquine touted its benefits in a letter in BioScience, but the data underlying the claim have not been published. All in all, more than 20 COVID-19 studies in China used chloroquine or hydroxychloroquine, WHO notes, but their results have been hard to come by. “WHO is engaging with Chinese colleagues at the mission in Geneva and have received assurances of improved collaboration; however, no data has been shared regarding the chloroquine studies.”
Researchers in France have published a study in which they treated 20 COVID-19 patients with hydroxychloroquine. They concluded that the drug significantly reduced viral load in nasal swabs. But it was not a randomized controlled trial and it didn’t report clinical outcomes such as deaths. In guidance published on Friday, the US Society of Critical Care Medicine said that “there is insufficient evidence to issue a recommendation on the use of chloroquine or hydroxychloroquine in critically ill adults with COVID-19.”
It looks like getting data from the French and the Chinese is like pulling teeth. I don't get the secrecy. It's kind of BS you expect from these countries in the normal course of events, but these aren't normal times.
Easy. China is at war with us. Has been, on the down low, for decades. They don’t want us to know the secret to how it is best treated.