Unvaccinated California Teacher Caused COVID Outbreak That Infected Half Her Class

A single unvaccinated teacher at a Northern California school triggered a COVID-19 outbreak in May that infected 26 others, including a total of 18 students, the Centers for Disease Control and Prevention reported Friday.

News of the startling, rapid spread in the school and to students’ families emerged as administrators grapple with vaccine and mask regulations for another school year in the face of Republican governors blocking mask mandates.

At least 90,000 students across the nation have already been quarantined at the start of this school year after contracting COVID-19 or being potentially exposed to the coronavirus. Children accounted for more than 1 in 5 new cases last week, according to the American Academy of Pediatrics.

The recent case examined by the CDC involved a Marin County school with 205 students from kindergarten through eighth grade.

Although teachers and students at the school were required to wear masks and maintain social distancing indoors, the unidentified teacher who caused the infections had removed her mask “on occasion” to read aloud in her class, the CDC noted. Student desks were placed six feet apart, windows were left open, and all classrooms had high-efficiency air filters, the study noted.

The teacher worked on May 19 and 20 while experiencing early COVID-19 symptoms before testing positive and taking sick leave. By May 22, students also began experiencing symptoms, the CDC reported.

Of the teacher’s 24 students, 12 tested positive; eight of them were seated in the first two rows of the classroom.

An additional six students in another grade also tested positive. Parents and siblings of students in both grades were also infected. Three of the adults who tested positive were fully vaccinated, according to the CDC.

“The introduction of the virus into the classroom by a teacher … while she was both symptomatic and unvaccinated, and who was unmasked when reading aloud to the class, resulted in cases within the classroom, across the school and among families of students,” CDC Director Rachel Walenksy said at a White House COVID-19 briefing Friday. 

“We know how to protect our kids in school,” she added. “We have the tools.”

Dr. Lisa Santora, deputy health officer for Marin County, said officials had been urging teachers to be vaccinated since January, but many had not done it. “We saw firsthand that it wasn’t kids who were going to get teachers sick. It was going to be the reverse,” Santora told CNN.

Among those who tested positive in the outbreak, 81% reported symptoms, including fever, cough, headache and sore throat, the CDC reported. No one was hospitalized.

The outbreak “highlights the importance of vaccinating school staff members who are in close indoor contact with children ineligible for vaccination as schools reopen,” the CDC study warned, as well as the delta variant’s “increased transmissibility and potential for rapid spread, especially in unvaccinated populations.”