et al., J. Medical Virology, July 9, 2020, doi:10.1002/jmv.26286 (preprint 6/29) (Peer Reviewed)
Chronic treatment with HCQ provides protection against COVID, odds ratio 0.51 (0.37-0.70).
The actual benefit is likely to be larger becasue research shows that the risk of COVID-19 for systemic autoimmune disease patients is much higher overall. Ferri et al. show OR 4.42, p
<0.001 , which is the observed real-world risk, taking into account factors such as these patients potentially being more careful to avoid exposure.
Ferreira et al., 6/29/2020, retrospective, database analysis, Portugal, Europe, peer-reviewed, 3 authors.
risk of COVID-19 case, 47.1% lower, RR 0.53, p < 0.001, adjusted per study, odds ratio converted to relative risk.