Thread by @MonicaGandhi9

Entire Bay Area is back in CDC's orange and red tiers for COVID spread - right, but this is because a highly vaccinated place will always be at risk of being in these "tiers" due to the outdated definition of the CDC's metrics of community spread.
sfchronicle.com/health/article…

To put it most simply, he current CDC guidance states that masks should be used in areas of high to substantial transmission (based on test positivity and cases/100,000 rates) but those metrics only made sense when mass asymptomatic testing was occurring prior to vaccination.

After vaccination, per the CDC guidance, only those with exposures or symptoms should test so tests are likely to reveal positive cases, which is not a good measure of community transmission or spread (but just means the people who should test are testing). Marin mask mandate

dropped Monday and "the county’s health officer Matt Willis said last week that an increase in cases alone will not determine whether masks come back; rather he will watch hospitalization numbers, which as of Friday were at a four-month low." @syramadad that makes sense!

CDC says drop masks when COVID cases <5 in 10,000 people past 7 days. Before vax, cities like SF did mass asymptomatic testing & that number gave idea of community spread. After vax, CDC says only test if exposed/feel ill so those 5/10K show right people testing, not viral spread

So, if CDC doesn't change this definition of community spread after vax, highly vax'd places (most likely to follow CDC) will be masking forever with this artifactual metric. Marin County broke from this definition Monday; America losing the plot
theatlantic.com/health/archive…