crowd with masks

An outdoor mask mandate is back, albeit for very large gatherings only.

If you're not in the business of obsessively following Public Health Twitter on the eve of a holiday weekend, you may have missed a very welcome development on Friday.

That day, Public Health—Seattle and King County unveiled a critical and, until then, absent tool for assessing risk amid the Delta stage of the coronavirus pandemic. In doing so, it cleared up a ton of uncertainty about who is actually getting sick with the more contagious form of the virus.

On a new data dashboard, the authority displays some telling stats. Over the past 30 days, and adjusting for age, unvaccinated people are seven times more likely to test positive for Covid-19 than those who have received their shots. They are 49 times more likely during that span to be hospitalized with the illness, and 32 times more likely to die of it.

While we've long known that vaccines are effective in preventing severe bouts of the disease, there's been more than a little trepidation that, in our highly vaxxed area, cases have remained high for weeks. King County recently added an outdoor mask mandate for outdoor gatherings with 500 or more people. It had already reinstated an indoor mask mandate.

But the public health authority's data plainly shows that vaccinated people are far more protected against Covid-19 than those who've rejected or cannot receive the shots. Though King County's calculations rightly weight for age, even a raw proportion (a feature on the dashboard) shows that vaccinated people have never made up more than 40 percent of weekly cases here, let alone hospitalizations or deaths.

Parents awaiting vaccine authorization for their children can take at least some solace in the demographic breakdowns, which show that people under 12 are far less likely to contract severe Covid cases than even unvaccinated 20-somethings. (The dashboard does not, unfortunately, capture these demographic trends over time, so it's hard to say if that comparison has changed in recent weeks.)

Yes, there are still questions left unanswered, like how frequently vaccinated people can transmit the virus to unvaccinated, or vaccinated, loved ones and strangers. But the dashboard offers much-needed context as families weigh decisions about schooling and returning to massive indoor gatherings this fall.

King County will update the data every week, with a one-week lag. You can find the new dashboard here.