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President Biden vowed to “follow the science” in an effort to get kids back to school. But that’s not what the latest school opening guidelines from the Centers for Disease Control and Prevention do.

The two core pillars of the guidelines — that schools should decide whether to open based on community transmission and that students should strive to be spaced 6 feet apart — aren’t supported by science.

While there are many prudent recommendations in the document, these two demands will keep schools closed much longer than necessary, harming kids.


Should learning mode depend on community transmission levels?

The new school opening guidelines advise schools to open or close (or operate in “hybrid” mode) based on a four-tier color-coded system. Each color is tied to the number of new Covid-19 cases during the previous week. The red, or most restrictive category, is more than 100 cases a week per 100,000 people. By this metric, more than 90% of the country is currently in the most restrictive tier, ruling out full-time, in-person learning for elementary-aged students and any sort of in-person school for older children without screening tests.

Yet many schools in such communities already have in-person school — and have done so for months — without issue.


To justify this tiered approach, the CDC guidelines cite a “likely association” between community transmission levels and the risk of exposure in the schools. But the evidence for this is flimsy.

The CDC relies almost exclusively on a U.K. study that examined Covid-19 cases and outbreaks — defined as two or more linked cases — in educational settings in England during June and July. The CDC summarizes the study by noting: “For every 5 additional cases per 100,000 population in regional incidence, the risk of a school outbreak increased by 72%.”

While technically true, that increases is the relative risk, which obscures the study’s key finding about absolute risk: School outbreaks were vanishingly rare in this study —just 0.02% among schools that were open daily during this period — even in areas with high rates of community transmission. And if the CDC had looked at the next figure in the article, focusing on individual infections rather than outbreaks, no association was seen between the number of single infections in school and broader rates of community spread.

The CDC’s school opening guidelines also ignore the experience of at least two U.S. states. Schools in North Carolina and Wisconsin were open during periods of high community transmission (red zone), and both saw far fewer cases in schools than outside of them. The Wisconsin study was published in Morbidity and Mortality Weekly Report, the CDC’s own journal. If the state had taken the CDC’s advice, it never would have done the study in the first place. Moreover, if there is less viral spread in schools than in the community, we want them open precisely during periods of high community spread, when the comparative risks outside of school are highest.

Do schools drive the spread of Covid-19 in the larger community? The CDC guidelines cites two studies. One, using national data, found no overall increase in hospitalization in counties where schools opened this fall, relative to trends during the same period in areas where schools remained closed. For counties with the highest rates of Covid-19 spread when schools reopened, some estimates showed an increase in Covid-19 hospitalizations, but these effects were quite modest, on the order of 2% to 3% above baseline levels of hospitalization. Even if this difference is real, it is quite small and unlikely to overwhelm the health care system unless it is already at the breaking point.

A second study, focused on Michigan and Washington, suggested that schools can contribute to transmission when exiting case counts are high. But this analysis was vulnerable to a classic research problem of reverse causality: school reopening may have led to more frequent testing and detection of infections that would have otherwise gone unrecorded.

Put together, the available evidence offers little reason to believe that in-person learning is particularly risky to students, educators, or people in the community. We believe the benefits of school far outweigh these concerns, and this is especially true as vulnerable people get vaccinated.

Is 6-foot distancing really required?

The CDC guidelines say that schools should try to keep kids 6 feet apart. This guidance, however, appears to be based on decades-old research on the travel distance of large respiratory droplets.

The insistence on 6 feet was controversial from the start. One of the early skeptics was physician Rochelle Walensky, who was recently appointed to lead the CDC. She advised her local school district last summer that “it is quite safe and much more practical to be at 3 feet” as long as everyone is masked. (Three feet of distancing is also recommended by the World Health Organization.)

When asked to explain this about-face during a recent interview with CNN, Walensky argued that the larger distance in the CDC guidance was justified by new research published since last summer and the increase in case counts since then.

The newest evidence actually seems to argue against requiring strict adherence to a 6-foot rule, however. First, it is increasingly clear that transmission of Covid-19 is not explained by the droplet model — the idea that bigger drops of secretion fall in the first few feet around someone, as was thought when the original social distancing guidelines developed. Second, a meta-analysis on Covid-19 and other closely related coronaviruses showed that the benefits of increasing the distance from 3 to 6 feet is marginal in contexts where the risk of infection is low, as would be the case in a classroom with universal masking.

Most on point is a recent study that examined the dynamics of in-school transmission in Ohio. Working with seven school districts that offered in-person learning in late November and early December of last year, near the peak of daily recorded infections in the state, researchers identified all students and teachers who had tested positive. They then repeatedly tested both their close contacts — other students who were exposed for more than 15 minutes at a distance of less than 6 feet — as well as a comparison set of students who kept their distance, including several hundred attending other classes within the same school. The rates of infection among close contacts and students who stayed more than 6 feet away were nearly identical in both elementary and high schools, suggesting minimal value from strict adherence to a 6-foot distancing rule as long as masks are worn consistently and correctly.

Three feet versus 6 might sound trivial, but it really matters. Given the limitation of classroom size, maintaining 6 feet of distance will thwart many schools from operating at full capacity, meaning that students would be able to attend part-time at best, using a hybrid model.

This requirement also complicates transportation. Although the main CDC guidance does not discuss transportation in detail, an accompanying handout advises districts to “skip a row if possible” on school buses. The busing constraint is particularly binding in large urban districts, where many students attend charter or magnet schools far away from their homes and rely on district-provided transportation.

Going backward on reopening

Rather than moving the ball forward on Biden’s goal of getting elementary and middle schools reopened as soon as possible, the new CDC guidelines will work to provide political cover for interest groups and districts that want to delay in-person school.

They also come when many states were acting to loosen their own guidelines to encourage schools to reopen. Just days before the CDC announcement, the state of Massachusetts announced the elimination of school bus capacity limits as long as bus windows remain open at least 2 inches. Nevada, which already allowed closer spacing on school buses, also loosened its requirements further. But, the new CDC guidelines would thwart these pragmatic efforts. The conflicting CDC guidance only creates confusion, putting districts in the difficult position of deciding whether to follow state or federal recommendations.

Most worrisome is that the stringent CDC criteria will likely increase pressure to reduce in-person learning in many places that have been operating at full capacity and with older students. As recent test score data from Ohio show, moving from in-person to hybrid formats will exacerbate learning losses, compounding the both the social and academic harms students have already experienced during the pandemic.

A truly science-based analysis must recognize the difficult tradeoffs involved — including the long-term of interests of children who are most directly affected — and carefully weigh modest increases in Covid-19 infection risk to educators and broader community members against the harms of school closures.

By promoting slavish adherence to arbitrary benchmarks and distancing requirements, the new CDC school opening guidelines do a disservice to science and kids.

Vladimir Kogan is an associate professor of political science at the Ohio State University. Vinay Prasad is a hematologist-oncologist and associate professor of medicine at the University of California, San Francisco.

  • People that are wanting to open schools are ignoring the fact that this bug does not care if you’re a child or an adult. It will spread if giving given any opportunity to a human host regardless of age.

    While the children may not display any symptoms, they are ALL possible vectors of transmission unbeknownst to the adults gazing upon them. Johnny and Susie will then spread the disease to their teachers, parents, or grandparents. The healthcare professionals in our communities will then be tasked with taking care of these older people, thus placing their own lives in jeopardy for the sake of Johnny and Susie being allowed to work & play at school.

    The answer to this situation is vaccinate, vaccinate, vaccinate! If the healthcare professionals, teachers, and the adults are vaccinated, then the chain of transmission can be broken at least among those in the older age brackets where the worst effects of the bug have been seen.

    I am so tired of this being deemed a conspiracy and American adults acting like a bunch of babies not willing to get vaccinated. Grow up! Put on your big boy boots Johnny.

    • None of the vaccines are certified for use with children. Not recommended for anyone under 18.

  • no mention of recent published data that in the states nationwide 80% of the deaths due to covid 19 occur in the elderly population that are 65 years and older

    • No mention of Long Covid either, and it affects all ages. Some of those folks may never be well. This part of the disaster is still not recognized. It’s not even in Biden’s “Covid Plan”.

      Unfortunately for the people with Long Covid, they will be disbelieved and denied access to social and medical support. Instead, they will get a web link to computerized “Cognitive Behavioral Therapy”.

  • 1. Why in the world is STAT publishing an opinion article on the “science” of reopening schools, written by a political scientist and a hematologist/oncologist? This is beyond laughable.
    2. Are testing and contact tracing in the US at high enough levels to say that even the CDC school reopening guidelines are “safe”? That is the real question.
    3. About 10% of COVID patients are estimated to have longer-term symptoms that are often quite debilitating. This is almost never reflected in COVID stats, which focus on deaths. If we weren’t also experiencing >3,000 deaths a day, the number of people with long-term illness would be deeply alarming. Which brings me to:
    4. After a year of atrocious public health mismanagement and active disinformation by the previous administration, we in the US have become inured to an obscenely high rate of illness and death. It is only within that context that this opinion article makes any “sense” whatsoever.

    Shame on the authors for this article, and shame on STAT for publishing it.

  • I’ll just say two things:

    1. Schools tend to be hosts for most illnesses, and it’s quite apparent when you work or attend classes and witness just how easily and more often you end up getting sick. Thus, if schools have proven themselves to not be major hosts for this particular pathogen, then it simply proves how overblown SARS-CoV-2 truly is.

    2. Regarding distancing and masking requirements, let’s be realistic here: Nobody can force students to abide by these rules, and outside of school I absolutely guarantee you that students are congregating and playing for the most part like normal. Thus, once again, proving that despite SARS-CoV-2 supposedly running rampant throughout the world, it hasn’t dropped these students like flies despite most of them probably having already been exposed to it.

    • Schools all over the world re-opened in May 2020, following dozens of studies showing rates of transmission are low between children and nearly infinitesimal from child -> adult. Months and months passed while the main stream despretly seeking that first “case” of child to Adult transmission. Iceland dug in deeper and thought they were missing something and did a full-on genome study, their results? No child to adult transmission was found, none. Referencing SARS-COV1 T/B-Cells and the nearly same breakdown on RNA as SC2 – immune systems with built in breakers. Some of those countries abroad never closed their schools and installed zero mitigation measures and when compared to US schools with all the millions of $ spent in such measures – their outputs were the same. We have not researched the second hand output of installing these measures. In which those have proven to raise suicide rates and drug related overdose rates at near exponential outbreaks. Now OCD/PTSD cases are starting to trickle in and are sure to explode once the data hits journals. The scariest aspect of these measures which has not be mentioned once (to my knowledge) is the low term impact of damaging our childrens immune systems. We know that masking doesnt block viral pathogens but do know they block bacteria (and host bacteria) both good and bad. Robbing our children of the ability to safely mix good/bad bacteria which has lead to Teachers have top 3 immune systems in all careers, will have what impact? We don’t know? We don’t discuss it and just pretend that this is all for their “safety”

  • In Indiana our 4,000-student district has been open at 100% capacity since August. I work with the district nurse contact tracing students. The amount of students that test positive for COVID during their time quarantined is almost 0. Why should we still follow science from August when there’s more current science from Sept-Feb. All of which seem to point to the ideas in the article that 3′ distancing with masks is safe enough.

  • Thank you for your brave and important article. The safest way to avoid car accidents is to stay off the road but we still drive. These closures are extremely harmful to children and exacerbate all kinds of inequalities.

    • I have to second this doctors comments. I have been teaching since September safely. In person is the only way I feel fully effective as an educator. I still have four students whose families keep them home and I try to keep them up on the curriculum but it’s incredibly hard to teach in that format. And teaching both in person and online every day is double the work for me, frustrating and I’m paid no more than usual~which is a pittance. I would like to not teach remotely next year and I’m hoping that families will see that children are actually safe at school. Everyday, we play outside, we work outside as much as possible, I keep the windows open for fresh air and we are all masked…none of us have gotten sick this year.

  • This is a very flawed article, lacking science. There had been study that droplets, especially smaller one cause by breathing can travel farther than 6 feet. If you have active airflow in the room like AC blowing or a fan, that could make it travel further.

    Disposable surgical mask becomes useless after a few hours once it becomes moist from breathing. Assuming everyone wear mask properly and no leakage, then you should be safe, the problem is most people don’t wear mask properly. And there is really no fitting mask for small kids.

    As we have seen with flu, the children in school are the one who usually bring the flu back home.

    It may be safer for mid School and above to reopen school, but probably not for elementary and below.

    Maybe we can make class shortage by removing classes that are useless.

    • “Disposable surgical mask becomes useless after a few hours once it becomes moist from breathing”

      Well that is an interesting claim. Yesterday I read a paper (can’t remember where!) that claims it is the increase in airway humidity caused by the mask that makes them effective. Which claim should I believe? Are both claims wrong?

      We are drowning in conflicting information and leaders wonder, “Why don’t they accept and obey today’s version of The Rules?” It was stunning to see Fauci publicly admit to changing his story in order to manipulate us into compliance. Even more stunning, he made that admission and still keeps his job.

      Meanwhile few notice that the goal is not to eradicate the virus. If the goal is not to eradicate the virus, then it must be something else. Let it become endemic so as to sell annual vaccines forever?

  • Just vaccinate the teachers and staff. With new variants expanding, best to err on the side of caution and common sense.

  • Thank you for this excellent synthesis. It is good to see, but also very disheartening because it just adds to a pile of evidence that schools are safe to reopen. This has been explicit for months. Yet the issue has become so politicized that no one seems to care about the evidence anymore. Here in CA, it’s a standoff. We’re at nearly a year of closures. The harms are real and will last. Trust in our educational leadership has broken. The discussion has been centered around teachers fears, and misinformation has been rampant. Wonderful, pro-science, reasonable people cannot hear anything written in this article. It’s shocking and deeply sad. In the meantime, it seems that our children’s well-being is really nowhere in the discussion. Lots of “we understand how hard it is,” but no willingness to do anything differently. Thank you for your ongoing advocacy.

    • “children’s well-being is really nowhere in the discussion”

      Stunning rates of childhood poverty, hunger, and homelessness are good evidence that US society considers children to be as important as all the disposable “essential workers” forced to work in unsafe conditions without adequate PPE.

      Children died from hypothermia, carbon monoxide, and fire in Texas this past week. And the national response to this latest crisis is… crickets.

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