As I assess potential New Year's Eve plans with the intent of spending several days indoors immediately thereafter with my parents (early-to-mid 60s, one has mild-to-moderate asthma but probably healthier than your average 60 year old otherwise [1]), I've been struggling to figure out how to use microCOVID.org given Omicron, boosters, and potential rapid testing.

Here are my working assumptions for everything but testing:

https://docs.google.com/spreadsheets/d/1yZqJKyzPu4CuNFfSR7Tq_QFgSEKrNll-n6iFB-Ly4jw/edit?usp=sharing

For rapid tests, I plan to multiply by a factor of 30% based on Tornus' post citing a 75% reduction in risk from a BinaxNOW test. I cut it down by 5 percentage points arbitrarily to reflect some uncertainty around how sensitivity varies for omicron. Uncertainty comes from the following:

• Preliminary results from the NIH: https://www.politico.com/news/2021/12/28/fda-antigen-tests-reduced-sensitivity-omicron-526217?fbclid=IwAR22ulLUhteXrFdhFiuYMLa35Ha1BXFNT_z4QlA6f6ql3nSO8tQ2Q7_WfoU
  • Michael Mina explains this means "ALL tests will falter on day 1" (not that rapid antigen tests are uniquely bad), but I imagine that doesn't change the fact that rapid tests are less accurate for Omicron?). He notes that UK Gov found no impact on sensitivity for Omicron, but it seems like a lot of tests in the UK recommend throat swabbing, and that could impact accuracy for Omicron for tests like BinaxNOW which are nasal only)
• This: https://www.businessinsider.com/how-to-trust-rapid-covid-test-result-2021-12?amp&fbclid=IwAR3pio-S_xkw4uUOL07sy1lYTapjOBGzRm1iHg0Pe0GFL5aJ1NUXpYfmCGs

[1] In practice, I plan to navigate this by doing rapid tests every day I am with my parents, and masking indoors with a KN95 for at least the first day. Still figuring out how risky a gathering I am willing to attend given that (hang out with a few people indoors with rapid tests beforehand? Plus masks?).