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 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.
Severity of disease is not analyzed as compared to humans. The steep viral drops observed could also be related to immune system response.