The picture is from https://science.sciencemag.org/content/368/6493/829
published "22 May 2020" at the time when less was known about Chloroquine and hydroxychloroquine than today about treating Covid-19 (1). That's the needed perspective when watching the picture, where the rest is still relevant.
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1)
E.g. June 23, 2020 "NIH: Trial Investigating Hydroxychloroquine for COVID-19 Stopped"
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1)
E.g. June 23, 2020 "NIH: Trial Investigating Hydroxychloroquine for COVID-19 Stopped"
https://www.empr.com/home/news/hydroxychloroquine-trial-halt...
17 June 2020 "“Solidarity” clinical trial"
https://www.who.int/emergencies/diseases/novel-coronavirus-2...
"hydroxychloroquine does not result in the reduction of mortality of hospitalised COVID-19 patients, when compared with standard of care."
And before, Jun. 9, 2020: "Three big studies dim hopes that hydroxychloroquine can treat or prevent COVID-19":
https://www.sciencemag.org/news/2020/06/three-big-studies-di...