But the variant may fuel outbreaks in unvaccinated communities and populations.
“We are vaccinating more people every day, but we are not on a trajectory to be able to interrupt transmission by the fall,” said Dr. Sean O’Leary, a pediatric infectious disease specialist in Colorado. “Unless we can do that, just about everyone I know in the field is very concerned about a fall surge.”
Children are far less likely than adults to become ill from the virus or its variants. Fewer than 2 percent of children with Covid-19 end up in the hospital, and even fewer — .03 percent of cases or less — have died, according to the American Academy of Pediatrics. A small percentage may also develop a rare but potentially serious inflammatory condition.
The emergence of the Delta variant is an urgent reason to continue a variety of mitigation measures in elementary schools in particular, said Dr. Linas, who has an 11-year-old daughter who is not yet vaccinated.
What other precautions does the agency recommend?
The agency recommends what it calls a “layered” approach, suggesting that schools combine multiple mitigation strategies to reduce risk. (This has also been called the “Swiss cheese model.”)
In addition to masking, distancing and vaccination, schools could put in effect regular screening testing for the virus. Fully vaccinated students and staff members do not need to participate in screening programs or quarantine if they have been in close contact with someone with Covid-19 unless they have symptoms, according to the guidelines.
The guidelines also note the importance of ventilation, encouraging schools to bring more fresh air inside by opening doors and windows or changing the HVAC settings. “I’m glad to see ventilation called out specifically as a stand-alone item,” said Joseph Allen, an expert on healthy buildings at Harvard T.H. Chan School of Public Health. “We’ve been talking about this for 18 months at this point.”
Why isn’t the C.D.C. setting specific standards for schools?
At this stage of the pandemic, the agency said, one set of overarching rules does not make sense. Vaccination rates vary enormously across the country, and communities with low vaccine coverage may see significant outbreaks, especially as Delta spreads.