SAN FRANCISCO, Calif. (KRON) — The San Francisco Unified School District has a big decision to make before the fall, when 57,000 students will be returning to classrooms for in-person learning.

The district still has not made a final decision on whether it will require all students and teachers to wear masks when classes begin August 16.

The majority of school-aged children are too young to receive COVID vaccines. But some San Francisco teachers told KRON4 that they still want their classrooms to be mask-free for the new school year.

One of UC San Francisco’s top COVID experts agrees that, as long as all teachers are vaccinated and the city has herd immunity, classroom mask mandates are not necessary from a medical perspective.

SFUSD spokesperson Laura Dudnick told KRON4 that the school district is leaning toward requiring masks for this fall.

The school district issued this statement to KRON:

“Health and safety remain a priority. As COVID-19 conditions evolve, official guidance is not yet entirely clear for school re-openings for fall 2021. We’re planning for different possibilities given the projected conditions and eagerly await more guidance from state and local public health officials.”

No major COVID outbreak has been traced to any Bay Area school.

Studies conducted by the CDC during the pandemic discovered that — compared to other age groups — young children are far less likely to be infected by and spread the virus.

“Kids really don’t acquire or transmit the virus as efficiently,” said UC San Francisco infectious disease physician Peter Chin-Hong.

“One of the most interesting studies was early-on in the pandemic when they looked at the receptors, the Ace 2 receptors, which are the places or the doorways that the virus needs to enter the body through. They are very, very few, the younger the kid is. So because you have fewer receptors, or beds that the virus is trying to get to, it gets stuck it can’t really enter the body,” Chin-Hong said.

The decision for whether a student wears a mask in a classroom should be made individually by the child’s parents, Chin-Hong said.

As long as the adults — teachers, administrators, and parents — are vaccinated, medical experts do not believe that there will be spikes in COVID cases from children spreading the virus to each other.

“Kids in general are more protected. Of course they can still get disease. So you look at what is going on in the community. If the community prevalence is really really low, with a low-risk population, that combination is going to be close to zero,” Chin-Hong said.

San Francisco will likely be the first city in the U.S. to achieve herd immunity, tweeted Bob Wachter, chair of UCSF’s Department of Medicine.

San Francisco Mayor London Breed on Friday announced that 80% of eligible San Francisco residents have received at least one dose of the COVID-19 vaccine, with nearly 70% of all San Franciscans fully vaccinated. 

“With our numbers, 12 cases per day in a city of a million people in San Francisco … you’d have to go out and hunt for COVID right now like hunting for a unicorn,” Chin-Hong said.

When vaccines become available for children under 12, Chin-Hong said parents should get their youngsters vaccinated as well.

He said it’s important to remember that normally during a pandemic, children receive vaccines first — before adults. For COVID, the oldest age groups were prioritized to get the first vaccine doses because they were the most likely to suffer serious health consequences if infected by COVID.