“Late
last week the Centers for Disease Control and Prevention (CDC) issued updated guidance on school reopening, saying that 3 feet,
not 6 feet, of physical distancing between students was sufficient in most elementary
schools—regardless of the level of community spread of COVID-19.
“At
the same time that CDC officials were updating school policy, they were also warning that B117, a variant strain 50% more
transmissible than the wild-type virus, would likely become the dominant strain
in the United States by April. In some states, such as Florida and California,
the variant, which was first detected in the United Kingdom, already accounts
for 25% of cases.
“Now
several experts are concerned that schools may be opening during an inflection
point in the pandemic and are being misguided about how to do so.
CDC, states struggle with school openings
“Across
America almost all schools closed in March and April of 2020 as the pandemic
entered its first wave and peaked in places like New York City. A barrier to
reopening in the fall, especially in crowded, urban school districts, was that
classrooms could not accommodate students with the CDC-recommended 6 feet of
physical distancing.
“The
CDC said mounting evidence shows little difference in school transmission rates
when students are separated by 3 or 6 feet, and it points to mounting research
on student mental health, physical health, and even parental job security that
shows that in-person instruction is superior for most American children and
families.
“‘It's
a balance,’ said Ruth Lynfield, MD, Minnesota state epidemiologist. Minnesota,
along with Michigan, and North Carolina, has seen school-related B117 outbreaks spread into the community
in recent weeks. ‘We are in a race to vaccinate as variants spread, and
currently kids and their parents are not vaccinated, so communities need to
work that much harder to make in-person school happen,’ Lynfield said. ‘That
means wearing masks, and not gathering with other families outside of school.’
“Lynfield said she is seeing B117 cases increase yet at the same
time sees hope via vaccination. ‘But we could have another surge,’ she said. ‘And
nobody wants that.’
“Michael T. Osterholm, PhD, MPH, director of the University of
Minnesota's Center for Infectious Disease Research and Policy, publisher of
CIDRAP News, is worried B117 will lead to a different level of transmission
than the country has seen before. ‘We're already seeing substantial
transmission,’ said Osterholm, who had supported the opening of K-8 schools
given the dynamics of the wild type virus. Osterholm said the CDC
recommendations were based on data done when only the original, wild-type virus
was circulating, not B117. ‘What little science supports 3 versus 6 feet goes
out the window here. Is 6 feet even safe?’ he said…
Elephants
in the (class)room: Lunch and aerosols Room
ventilation is key
“When CDC Director Rochelle Walensky, MD, MPH, introduced the
3-feet guidelines, she cited a study recently published in Clinical
Infectious Diseases. That paper showed similar spread of the virus
in Massachusetts schools that
implemented masking and 3 feet of physical separation, compared with masking
and 6 feet. ‘The paper is asking the wrong question,’ said Lisa Brosseau, ScD,
a research consultant with CIDRAP. ‘Does 3 feet or 6 feet matter when kids are
in a classroom for 6 hours?’
“Moreover, the recommendation still ignores aerosol transmission
of the virus, said Donald Milton, MD, DrPH, MOH, of the University of Maryland
in College Park. ‘The concept of 3 feet or 6 feet is based on droplet spray in
the first place,’ Milton said. ‘If we were only talking about spray-borne
transmission, that distance is important. But that's not what's happening at
this point.’
“The Massachusetts study, according to Milton and Brosseau, also
fails to address the real-world challenges schools present to infection
control. ‘The elephant in the room is lunch,’ Milton said. ‘We know a high-risk
activity is dining. People can't eat with a mask on. I don’t see people talking
about that in the context of schools.’ The CDC's current guidelines suggest 6
feet of distancing should be maintained when students are not wearing masks.
“Brosseau said though the Massachusetts study, and thus the CDC
guidelines, focuses on face-covering policies, not enough attention is given to
the ventilation systems in school districts. ‘If those with less than 3 feet
policies also improved their ventilation, that would dilute the impact—so to
speak—of more people closer together. I suspect none of the districts made
any ventilation changes, but that would have been an appropriate variable to
include in their models,’ Brosseau said.
“Kim Prather, PhD, of the University of California San Diego, has
been helping San Diego Unified, one of the biggest school districts in
California, plan for its reopening on Apr 12. She said she is encouraging
schools to maintain 6 feet of distance. ‘If you tell kids 3 feet, it becomes 1
foot,’ Prather said. ‘And what worked for schools in the fall will only get
harder with the variant.’
“All of the experts agreed that safety opening schools must be a
top priority, but one that cannot be addressed properly until the CDC
acknowledges what it knows—and doesn't know—about the virus. Until then,
Prather is recommending that schools invest in ventilation, HEPA
(high-efficiency particulate air) filters, and close-fitting masks for kids.
She advised San Diego Unified to ban children who are not wearing masks from
coming indoors, and recommended lunch be served al fresco for the time being. ‘The
chance of things calming down right now are so close with vaccines,’ she said. ‘And
the variant can't take off unless you give it the opportunities’” (Center for
Infectious Disease Research and Policy, University of Minnesota).
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