How the Delta Variant penetrated elementary school classrooms

Unvaccinated primary school teachers infected with the highly contagious delta variant spread the virus to half of the students in the classroom, eventually causing an outbreak that infected 26 people. New report From the Centers for Disease Control and Prevention.

Very detailed studies conducted as school districts reopen across the country seem certain to intensify the debate about vaccine obligations in schools.A handful of school districts including New York City, Has already announced vaccine requirements for teachers and staff.

Now that the Food and Drug Administration has given full approval for the Pfizer-BioNTech vaccine, others may follow suit.

Jennifer Nuzzo, an epidemiologist at Johns Hopkins University, said: , Those who were not involved in the report.

This study was one of three new CDC reports focused on schools and children.In another study, researchers found more evidence that combined schools could create a low-risk environment. Some precautions.. However, the study was conducted before the delta variant began to spread.

NS Third report focused on Vaccination rate for teens. Half of 12-17 years old Received at least one dose The White House of the coronavirus vaccine was announced on Friday. However, new studies have shown that vaccination rates in this age group remain highly heterogeneous nationwide.

Together, the study emphasizes how much scientists have learned about how to protect children in school, and how uncertain they remain now that Delta variants have arrived.

The classroom outbreak occurred in May in Marin County, California. Neither the school nor the staff or students involved were identified.

The teacher first showed symptoms on May 19, but worked for two days before being tested. During this time, the teacher unmasked and read aloud to a class of 24 students, despite the rules requiring both teachers and students to wear masks indoors.

All students were too young for vaccinations that are only approved for people over the age of 12.

On May 23, teachers reported positive coronavirus infection. Over the next few days, 12 students also tested positive.

“I thought I respected its infectivity,” said Dr. Lisa Soundtrack, Deputy Health Officer at Marine Health and Human Services and author of the report, about the Delta variant. But its efficiency in overtaking the classroom “surprised and humbled” her.

In the classroom, the infection rate almost corresponded to the seating chart. Everyone in the front row tested positive, down to 80% in the first two rows.

In the last three lines, only 28% of the students were positive. “If the teacher doesn’t have a mask, move to the back of the class,” Edward Traver, an infectious disease fellow at the University of Maryland Medical Center, said in a Twitter message.

Six students in another grade of school also tested positive for the virus. Cases spread from school to the community. At least eight parents and siblings of the infected student, three of whom were completely vaccinated.

State health researchers sequenced virus specimens from many of the positive cases and found that they were all infected with the delta mutant. Samples from at least 10 students in the two grades were genetically indistinguishable. The results suggested that both grades of cases came from the same outbreak.

The researchers said the outbreak was likely promoted by both the high levels of infectivity of Delta and the fact that teachers did not follow the recommended safety precautions.

Tracy Ramhain, an epidemiologist at Marine County Health and Human Services and author of the new report, said: “You can’t just do one or the other.”

In other parts of the country, community sacrifices may have been even higher. Marin County has the highest immunization rate in California. The report noted that 72% of eligible people in the surrounding area were fully vaccinated, suggesting that a high rate may have prevented further infections.

In another new study, researchers focused on case rates in Los Angeles County. In Los Angeles County, some students and teachers went directly to school last year, while others went to remote areas.

Schools opened for face-to-face learning had to take a variety of precautions, including symptom screening, masking, physical distance, and contact tracking. During most of the period from September to March, especially during the winter surge, school case rates were lower for both teachers and students than for the county as a whole.

The survey results are Consistent with previous studies We found that when a school combined several safeguards, the school’s case rate was often lower than that of the surrounding community.

“Schools are in many ways safer places for young people because they are so structured and supervised,” said Dr. Santra, who returned directly to schools aged 9 and 11. ..

However, studies on school mitigation measures, including reports from Los Angeles, were conducted before Delta variants began to spread. This variant is about twice as infectious as the original version of the virus and is now the cause of almost all infectious diseases in the United States.

It remains uncertain whether the same type of precautions will continue to control variants in this year’s schools, and many schools have opened without the safety measures recommended by public health professionals.

Siobhan Flynn, a first-year student at a public charter school in the Washington area, is worried about classes starting on Monday. The school where Flynn works uses a layered protection approach that includes mask mandates, socially distant desks, and random tests for students.

“Children need to go to school, but I wish they had more money and plans to open the school safely,” Flynn said. “If all staff were vaccinated, many would find it much safer.”

Vaccination rates have increased in recent weeks as Delta continues to cause a surge in cases, hospitalizations and deaths nationwide. However, parents have been worried about sending young children who have not yet been vaccinated back to school.

According to a third CDC report, the FDA first approved the 12-15 year old vaccine in May, and by July 31, more than one-third had received at least one dose. More than half of the 16-17 year olds who were vaccinated a few months ago received at least one vaccination.

However, vaccination rates vary widely from country to country. Researchers have found that in Mississippi, only 11% of adolescents are fully vaccinated, compared to 60% in Vermont.

In an email, Dr. Westyn Branch-Elliman, an infectious disease researcher at Harvard Medical School, said the school was more involved in promoting vaccination for all eligible people in the school community, including through the establishment of vaccination clinics. I hope it will be. ” At school to improve access and ease barriers. “

Clinical trials of the vaccine in infants are underway. Pfizer states that the results should be available in September.