This video was cited in the "New South Africa 'super-variant' " thread,
https://www.youtube.com/watch?v=E1GF0H9V_1gIt was originally called (IIRC), "The Japanese miracle" but appears to have been renamed, "Ivermectin in Japan" although he discusses things other than Ivermectin.
This is a summary of most of the main points:
— Cases in Japan have dropped to a very low level, currently 79 new cases per day and 2 deaths per day out of a population of 126 million.
— Treatment of Covid-19 with Ivermectin has been (effectively) allowed since the 13th August in Japan. Cases peaked 12 days later and then declined.
— Vaccination rates in Japan are good but not massively higher than Canada, UK and the US. South Korea also has a high vaccination rate but is experiencing an up-tick in cases
— The Delta variant wave appears to have ended, possibly due to self-extinction due to too many mutations. A mutation has been found (A394V) which has affected the error-correcting protein nsp14. This means that errors in the virus are not being corrected and the resulting large number of mutations are making the virus unviable.
— The A394V mutation has been discovered in 24 other countries.
— More people in Asia, especially Japan, have the defence enzyme APOBEC3A. From memory, Japanese in America have had fewer deaths from Covid.
— The National Institute of Genetics and Niigata University is looking into how the APOBEC3A protein affects the nsp14 protein.
— SARS ended abruptly in 2003 and is now extinct.
— A drug to inhibit nsp14 is being worked on.
I am not convinced of the significance of the Ivermectin unless there was a rapid uptake as soon as it became available. The following probably made more sense before Google translated it: "The antiparasitic drug "ivermectin" shows the number of infections and deaths of the new corona in a country that is prophylactically administered for another disease in Africa".
I am not convinced that a drug to inhibit nsp14 would be perfectly safe as I suspect that it could increase the chance of an apocalyptic variant.
A point made in the comments is that the Japanese eat mostly fresh, unprocessed food and lots of fish. The high fish diet results in a low incidence of vitamin D deficiency. This, and greater levels of hygiene (such as mask wearing) would not explain the shape of the graph, however.
Julian F. G. W.