He says;
> Interestingly, in the only published cluster RCT to date during COVID19, surgical masks had an 11% risk reduction and cloth masks had no effect at all on the primary endpoint of symptom driven lab positive result
The actual study showed that with intervention, the scientists increased the rate of mask wearing from 13% to 42% -- and that 29/100 person uptake was enough to reduce Covid seropresence by 11% in the community. That's a huge effect! Fewer than half of the people in the villages were wearing masks and symptomatic Covid saw >10% reduction compared to villages without extra mask wearing. It's abundantly clear that the effect would be far greater with universal masking so to say "mask wearing only leads to a 10% reduction" omits a massive part of the story.
https://www.poverty-action.org/sites/default/files/publicati...
To quote the authors who tried in vain to prevent people like Vinay from mangling their research:
> Our results should not be taken to imply that masks can prevent only 10% of COVID-19 cases, let alone 10% of COVID-19 mortality. Our intervention induced 29 more people out of every 100 to wear masks, with 42% of people wearing masks in total. The total impact with near universal masking–perhaps achievable with alternative strategies or stricter enforcement–may be several times larger than our 10% estimate. Additionally, the intervention reduced symptomatic seroprevalence more when surgical masks were used, and even more for the highest-risk individuals in our sample (23% for ages 50-60 and 35% for ages 60+). These numbers likely give a better sense of the impact of our intervention on severe morbidity and mortality, since most of the disease burden is borne by the elderly. Where achievable, universal mask adoption is likely to have still larger impacts.