With the Delta variant of Covid-19 infecting more children, many parents are worried about how to keep their unvaccinated young kids safe as schools reopen and extracurricular activities resume.

The best protection against Delta, doctors and public health officials say, is vaccination. But that doesn’t directly help children under 12, who are ineligible for the shots. So parents must weigh the risks and benefits of fall activities, from in-person school to sports, play dates and birthday parties.

Most parents by now know the basics: Masks reduce transmission and outdoors is safer than indoors. Beyond that, doctors suggest some principles to guide decision-making this fall. Give priority to your most important activities, they say, and skip others. Within your selected activities, look for ways to lessen risk.

“Almost nothing at this point is zero-risk,” says Leana Wen, an emergency physician and public health professor at George Washington University in Washington, D.C. “Do those activities and reduce risk in those activities, and then try to cut out the other activities that are higher-risk and lower-value.”

Risk accumulates with each activity, she notes. Don’t assume that if you are engaging in one higher-risk activity that you might as well do others.