This was posted on my FB:
My updated COVID post: (thoughtful, respectful responses are welcome, even if you wish to disagree with some of these points)
1. Vaccines: cases. We are seeing some interesting data about how well vaccines prevent infection, hospitalizations and deaths. Some of the stats are misleading. “The reported share of COVID-19 cases among those not fully vaccinated ranged from 94.1% in Arizona to 99.85% Connecticut.”(reference in comment 1) The problem here is that this just reports “total unvaccinated who got infected”/total who got infected” and this includes cases that occurred when vaccines were just getting going.
A more useful stat would be “infection rate of unvaccinated” vs. “infection rate of vaccinated” IN THE SAME location (don’t compare Vermont to Arkansas” and the first figure I show does that in San Diego County. It appears that in a similar situation, an unvaccinated person is about 9 times more likely than a vaccinated person to get infected.This area: 18 cases per 100,000 in a week for unvaccinated vs. 2 per 100,000 vaccinated. In an area with 100000 people, and say, 60 percent vaccinated, this would be a case rate of (.6)(2) + .4(18) = 8.4 per 100000, with 23.8 percent of cases coming from vaccinated people.
2. However, vaccines are even much better at preventing hospitalizations and deaths. Example: of the 125000 breakthrough infections recently recorded, there were 1400 deaths. That is 1.12 percent. But given that one has a much lower chance of even being infected to begin with, that is outstanding protection against death. The US ratio is 1.74 percent for all cases (vaxxed and unvaxxed)
3. Masks and spread (see reference in second comment)It turns out that the spread is primarily aerosol. It was first thought to be droplets because the “droplet” spread model fit well for reasonably ventilated spaces. But for poorly ventilated spaces, it appears to be aerosol, which means that one can get infected even if one is well away from the infected individual.But the big deal is that, formerly, it was though that aerosol droplets were 5 microns in size or less; it turns out that it is about 100 microns or less.So, as before, masks work to keep the infected from spreading it AND a good mask does provide extra protection for the non-infected as well, even in this aerosol type situation.
4. Delta is much more infectious; a brief encounter can induce an infection (not as true with the previous variants) So it isn’t surprising to see cases go up so rapidly.5. A vaccinated person who gets infected carries about the same load as an unvaccinated person. Vaccines reduce the spread as a vaccinated person is less likely to get infected. My own practices:1. I mask outdoors (2 layer fabric or better) if I will be around people (say at a game concourse, or if some are sitting somewhat close to me..often not the case 2. I use a special 3 layer mask indoors for the gym (my two gyms have good ventilation, high ceilings, and are often not crowded3. I use KN 95 for other indoor things where I am around people I don’t know.4. I avoid excessively crowded things (Chiefs games are not a problem)
5. I don’t mask for small gatherings of known, trusted, vaccinated people who are asymptomatic. I do isolate from infected people.
Hope: we ARE starting too see more people getting vaccinated.
