our children safely in school before we have vaccines. so now, today, what do we have for our children? we have vaccines, of course, that we can use, and we have school testing programs, we have new science that demonstrates tests to stay, and this is where a child might be exposed in the classroom, but if they're exposed, they don't have to stay home in quarantine, they can test every other day or twice a week, and stay in the classrooms safely, and what that has demonstrated is hundreds of thousands of person days. of children in school rather than at home. we have new science that has demonstrated the value of masking. three 1/2 times increased risk of school outbreaks if you're unmasked in schools versus if you're masking in schools. and just this week, we updated our k-12 guidance so that it is consistent with our isolation and quarantine guidance, with the general public so people can come back to school after isolation, after five days. >> thank you, dr. walensky, for that. and for your commitment to keeping our schools open. final quick question, for you, talking about inhome tests,