mindstalk | (Reply)

And just as, for STD purposes, when you have unsafe sex with someone you're in a sense having sex with everyone they've had sex with in the past year, so for covid purposes, once you mingle unmasked with strangers, you're breathing not just their air but all the air they've shared over the past week, and all the other safety in your life stops mattering. Or matters in limiting how often you roll the dice of infection, but still, you're rolling at all.

This is a good first approximation, but if you have good information about the status of the people you're interacting with, the individual risk calculation is slightly different due to incubation periods. Just as an exposure event more than two weeks past is unlikely to have a bearing on the infectiousness of a person you're interacting with today, an exposure event less than three days ago also is unlikely to have an effect. So, if you could trust a set of people to observe stringent precautions for a two week interval beforehand, you should be able to hang out with each of them within a span of a weekend without too much increase to your risk profile, even if they are doing something similar with a *different* group of friends. Network trust is a problem, though, and on COVID precautions (moreso than STDs) I think that a lot of people really don't have a clear idea of what behaviors are and aren't risky.

As with STDs, testing frequency also changes things. The institution where I teach is going to be testing all members of the campus community *three times per week* until the current surge ends (this is in addition to mandatory masking and mandatory boosting). That changes the risk profile even for interacting with people who engage in riskier behaviors outside of the campus setting.