With the COVID-19 delta variant surge once again prompting the Centers for Disease Control and Prevention to recommend masks indoors for teachers and other vaccinated school employees, many parents are left wondering if the new landscape of the pandemic means it's safe for their still-unvaccinated young children to return to school this fall.
Early in the pandemic, epidemiologic data showed parents a reassuring trend: children were less likely to be infected and more likely to have mild infections. However, as COVID-19 vaccines were rolled out and the country made progress toward herd immunity, there came a shift: The viral spread is now predominantly among the unvaccinated, and of the largest unvaccinated populations is children under 12, who are not yet eligible for the available vaccines.
Data from the American Academy of Pediatrics has shown that children have made up a higher proportion of overall COVID-19 infections over the past couple of weeks.
"This increase is concerning, and yet not surprising, as the virus is going to infect those who are not protected," said Dr. Amanda D. Castel, pediatrician and professor of epidemiology and pediatrics at George Washington University. "Children are still at risk for developing severe complications from COVID-19."
Fall classrooms will be ground zero for a recipe that epidemiologists fear: Unvaccinated populations combined with close proximity and limited social distancing could become an avenue for disease spread.
While children are not necessarily more vulnerable than they were before, the biology of the disease has changed. The delta variant is more transmissible regardless of age and spreads more efficiently across unvaccinated populations.
"Make no mistake, this is a virus that can cause children to suffer and die," said Dr. Paul A. Offit, pediatrician and director of the Vaccine Education Center at Children's Hospital of Philadelphia.
"We need a vaccine for 6- to 12-year-olds, and hopefully, we will have a vaccine on hand before we hit late fall or early winter, when this virus will no doubt surge again," Offit said.
An important question now circulates in parent and teacher circles: how do you mitigate risk and still give kids a normal school year? The CDC updated its prior guidance on Tuesday, saying that children and teachers should be wearing masks in school this fall.
Experts agree that a nuanced approach to preventing transmission and creating herd immunity with high vaccination rates is key.
"Teachers can enforce proper social distancing practices and keep extra personal protective equipment (PPE) for themselves and students in supply," said Kamon Singleton, M.Ed, a teacher at Heyward Gibbes Middle School in Columbia, South Carolina. "Although most schools may provide some PPE, teachers may want to keep an excess of supplies."
Castel said she believes "layers of protection" are the answer.
"The first layer is to have everyone who can receive a vaccine do so," Castel said. "Parents of children age 12 and older can make an appointment now. The shots create a bubble of protection not just for kids who have been vaccinated but also for kids who cannot get the vaccine yet. For those that can't get vaccinated, wearing masks."
While the pandemic is now largely fueled by those who decide not to vaccinate, this fall and winter, the focus will shift to keeping children from becoming the pandemic's next target until vaccines are available for all.
Nancy A. Anoruo, MD, MPH, is an internal medicine physician at Brigham & Women's Hospital and public health scientist. John Brownstein, Ph.D., is chief innovation officer at Boston Children's Hospital and an epidemiologist. Both are faculty at Harvard Medical School and contributors to ABC News' Medical Unit.