Pagliano et al., Clin. Infect. Dis., 2020 Mar 24, doi:10.1093/cid/ciaa320 (Peer Reviewed) (Theory) (not included in the study count) Is Hydroxychloroquine a Possible Post-Exposure Prophylaxis Drug to Limit the Transmission to Health Care Workers Exposed to COVID19?
CQ and HCQ inhibit replication at early stages of infection, no similar effect reported for other drugs which are only able to interfere after cell infection. Large volume of existing data on safety. (8/23: we corrected the classification of this study)
Pagliano et al., 3/24/2020, peer-reviewed, 5 authors.