et al., Nature, 2020, doi:10.1038/s41586-020-2558-4 (preprint 5/6) (Peer Reviewed) (not included in the study count)
Monkey study which reports no effect of HC
Q or HC
Q+AZ. However, there are actually several signs of effectiveness despite the very small sample sizes and 100% recovery of all treated and control monkeys.
58% reduction in lung lesions: the final day lung lesion data shows 63% of control monkeys have lesions, while 26% of treated monkeys do, p=0.095 (the final day data is missing for 7 monkeys, these are predicted based on the day 5 results and the trend of comparable monkeys).
97% increase in viral load recovery after one week: 3 of 8 control monkeys (38%) have recovered with <= 4 log10 copies/mL viral load, compared to 17 of 23 treated monkeys (74%), p=0.095. 3 of 8 (38%) control monkeys also have a higher peak viral load than 100% of the 23 treated monkeys post-treatment. The group with the lowest peak viral load is the PrEP group.
All animals were infected with the same initial viral load, whereas real-world infections vary in the initial viral load, and lower inital viral loads allow greater time to mount an immune response.