evidence: If COVID-19 spread like the flu, a community where none of the children and the majority of adults were not yet fully vaccinated would be in trouble. Unvaccinated, unmasked kids playing outside together, going to restaurants or movie theaters with their vaccinated parents and traveling on vacation to other communities would pose a meaningful risk to a lot of people besides themselves. So, it is a pretty big relief that this is not the case, and we’re seeing that fact echoed in new guidelines from the Centers for Disease Control and Prevention that classify unvaccinated people (including kids) hanging out unmasked, outside in the safest category — so long as the people they’re with are all vaccinated. That said, risks remain. Young children do transmit the virus, and variants like the more-transmissible B.1.1.7 lineage increase how likely kids are to spread COVID-19. It’s also important to note that those low rates of children transmitting COVID-19 are very dependent on behavioral modifications — in particular, wearing masks indoors. A brand-new study out on Thursday found that risk-reduction strategies like teachers wearing masks, kids wearing masks, checking symptoms daily and canceling extracurricular activities like sports made the difference between in-person schooling that spread COVID-19 from kids through their families and in-person schooling that didn’t significantly increase the spread of COVID-19.