Also, I think people who are interested enough to enroll in a clinical trial for a SARS2 vaccine are likely to be on the more cautious side. They probably don’t think the virus is a hoax, they’re probably not partying in crowded bars or going to Sturgis, even though they are out and doing things and coming into contact with others, they are probably taking slightly more precautions than the average person in their area. That’s my guess. That’s probably why Pfizer planned on an annual infection rate of 1.3% in the study’s placebo arm, well below the actual infection rate in hotspot areas, a term that is starting to include much of the country.

1.3% / yr is 0.11% / mo. About 2K received second dose by 8/27, about 15K received second dose by mid Sep, about 28K by first wk Oct, about 30K as of 10/26. If vaccine has zero efficacy, might back-of-envelope guess would have substantially exceeded 32 infections by now. So since they have not hit 32 yet, but are getting close per Pfizer, you can very roughly back into what vaccine efficacy likely is, and you can see why the CEO is confident. However, no-one knows if their 1.3% assumption is right. Pfizer said today that their assumption was “in the ballpark”, I don’t understand how they would know given blinding, though I haven’t looked at the blinding rules closely. The lower the actual infection rate in the placebo arm, the lower the vaccine efficacy could be consistent with the 32nd event to still not have been hit.

I’m rambling but anyway the reason people aren’t doing this sort of mental masturbation with the Moderna trial is because they played their cards closer to their chest. Thank goodness.