Very fresh, Mass General study not published yet even in preprint so take with grain of salt.
But they did a better job getting random sample than the guys at Hoover. Didn’t advertise, set up in town square and grocery store.
https://www.bostonglobe.com/2020/04/17/business/nearly-third-200-blood-samples-taken-chelsea-show-exposure-coronavirus/?outputType=amp&event=event25&__twitter_impression=true
