Education Week - September 8, 2021 - 4

Higher Rates of Delta Infection Projected for Fall
Delta Variant Outbreak Risks
A University of North Carolina study modeled the risk of COVID-19 infection for students over the course of a semester based on several
key parameters. They include: the percentage of students with some incoming immunity because they'd already had the disease or
were vaccinated; whether the school required universal masking, COVID-19 testing, or some combination of the two.
Low
Low Incoming Immunity (30 percent)
1.00
1.00
Mid
Medium Incoming Immunity (40 percent)
1.00
High
High Incoming Immunity (50 percent)
Without adherence to
masking, testing,
studies forecast
widespread infection
for teachers and
students
0.75
By Sarah D. Sparks
If districts don't tighten COVID-19 protection
efforts-and particularly for elementary
school students-outbreaks in schools this fall
could get ugly, fast.
New, in-review studies suggest that teachers
and students will become infected at higher
rates, and absenteeism will rise significantly in
schools that do not require universal masking
and weekly, systematic testing for COVID-19
and where the large majority of children have
not already been vaccinated or had the virus.
Moreover, earlier and wider spread of other
seasonal respiratory illnesses could make even
asymptomatic cases of coronavirus more problematic,
infectious disease experts warn.
School outbreaks will occur in those settings
where masks and other mitigation protocols
are not in place, " said Tina Tan, a pediatric infectious
disease specialist at the Ann & Robert
H. Lurie Children's Hospital of Chicago. " Children
can get very ill when they get a COVID-19
infection, so the attitude of 'just let them get
sick' is far from being OK. We need to do everything
we can to prevent the children from
becoming ill until they are eligible for vaccination. "
Two
studies modeling the transmission of
COVID in schools this fall have been published
in advance of peer review. They use data on
what we know about school outbreaks to date
and the potential spread of the Delta strain
of the virus-considered about twice as contagious
as the original virus-to predict what
might happen in different scenarios.
A sharp rise in school outbreaks has already
begun since Delta became the predominant
strain of the pandemic in midsummer. Schools
nationwide have reported record numbers of
new infections and closures due to quarantine,
including one Texas district that closed after
two teachers died from the disease in the same
week.
The American Academy of Pediatrics, which
tracks COVID-19 cases among children, found
that in the week leading up to Aug. 26, nearly
204,000 new coronavirus cases have been reported
among children, marking a 4 percent
increase from the previous week. As schools
enter the fall semester, the infection rate sits
at an eye-popping 6,374 per 100,000 children.
Among 12- to 15-year-olds alone, the youngest
group eligible for vaccines, the Centers for
Disease Control and Prevention finds the infection
rate has jumped sevenfold from the start of
June, to 168 per 100,000.
Models highlight masking, testing
practices
One of the new modeling studies, led by researchers
at the University of North CarolinaChapel
Hill, looked at scenarios in which a
school had a low, medium, or high number of
students and teachers who had already been
vaccinated or who had already recovered from
the virus. It also looked at the mitigation strate0.50
0.50
0.50
0.75
0.75
0.25
0.25
0.25
0.00
0.00
30
60
Time
in days
Scenarios
90
30
n No masking: Baseline
n Masking not required, systemic testing
required
60
Time in days
90
0.00
30
60
Time in days
n Universal masking required, systemic testing not
required
n Universal masking and systemic testing required
SOURCE: " COVID-19 Projections for K-12 Schools in Fall 2021: Significant Transmission Without Interventions, " University of North Carolina
at Chapel Hill.
gies being used, such as masking and testing.
In one scenario, a school required all students
and teachers to wear masks, tested at
least half of its students and teachers for the
coronavirus each week, and had a population
where there was a low level of incoming protection-like
an elementary school where no
students were old enough to be vaccinated. In
that scenario, about 22 percent of susceptible
students would become infected by the end of
the semester.
But across all scenarios of schools with no
universal masking or systemic weekly testing,
more than 3 out of 4 students who could get
COVID-19 would get sick. The researchers estimated
this could mean the difference between
140 lost school days for a school using masking
and testing, compared to 210 additional
absences in schools that did not.
A separate new study by University of California-Berkeley
researchers finds, similarly,
that in the highest-risk schools-where only
half or less of the school and community have
been vaccinated, and without mandatory
mask-wearing and systemic testing-a typical
elementary school holding in-person classes
could see 33 to 65 additional symptomatic infections
in a four-month semester, compared
to what would be seen among students in remote-only
learning, where they could not contract
the virus at school.
By contrast, in a region such as the San Francisco
Bay Area, which has about a 70 percent
vaccination rate and has reopened with universal
masking and other mitigation strategies, the
Delta variant could have a much smaller impact.
In that case, there could be eight to 36
new students with symptomatic COVID-19 in
a typical elementary school, 13 more cases in a
typical middle school, and three more cases per
high school, compared to the risk of infections
for those in remote-only learning.
Rates of teacher infections would be similarly
split. The researchers also found scenarios in
which schools that also kept students separated
4 | EDUCATION WEEK | September 8, 2021 | www.edweek.org
into small cohorts would have the lowest infections
compared to remote learning.
Schools must stress: Keep sick kids home
The new research highlights the need for
systemic testing on top of masking, as children
and those with the Delta strain are each more
likely to develop asymptomatic but infectious
cases of COVID-19, according to Kristina Bryant,
a pediatrician and professor of pediatrics
at the University of Louisville who is also a
member of the Society for Healthcare Epidemiology
of America.
" One mitigation strategy that we really don't
talk about is staying home when you're sick,
and that is really important, " Bryant said. " It's
totally understandable that parents need to go
to work and kids need to be in school, and a
couple of years ago we might not have kept kids
home with symptoms of a mild viral illness. "
But she added, " COVID-19 in many respects
looks like every other viral infection in children.
And if you say, can it cause wheezing, just
like RSV? Yes, it can. Can it cause a barky cough
like croup? Yes, it can, " Bryant said.
Administrators should be systemic in testing
and conservative in asking parents to keep students
home if they seem sick, she said.
Though separate, large-scale studies of
school mitigation strategies in North Carolina
and elsewhere were done before Delta became
the dominant strain, Bryant said their findings
also offer a roadmap to school districts in planning
how to start their school year safely.
" In North Carolina and in some other states,
schools opened when there was higher virus
[infection rates] circulating in the community
and kids were getting infected in the community,
but when it came to school, they didn't
transmit it, " she said. " I think time will tell,
things could be different with Delta, but for
now the data that we have suggested that when
layered mitigation strategies were in place,
then in-school transmission was minimal. "
90
"
Children can get
very ill when they
get a COVID-19
infection, so the
attitude of 'just let
them get sick' is far
from being OK.
TINA TAN
Pediatric infectious disease
specialist at the Ann & Robert H.
Lurie Children's Hospital of Chicago
Proportion of Susceptible Students Inffected with COVID-19

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Education Week - September 8, 2021

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