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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.

  • I appreciate your premise that reopening schools should be based on science. We also need to use COMMON SENSE. We closed schools to protect teachers, students and families. Logically, we should vaccinate teachers before resuming in person learning. Teachers need to be prioritized for vaccines before reopening. What is the point of vaccinating teachers AFTER exposure?

    • No the school environment has been proven to be among the safest so why should any of the protocols previously used be changed. The teachers are less likely to be exposed to the virus while at the school than anywhere else so why do THEY need priority vaccination just to do their jobs? It sounds like an excuse (and these days every reason to do not do something is because of the virus – really?) to stay home and expect more for doing less.

  • So the hundreds of teachers that have died is school opening ‘without issue’? Tell that to the 17 year old girl who lost both of her parents 6 hours apart. TEACHERS AND STUDENTS ARE DYING. HOW DARE YOU.

    • In person and remote teachers, according to science reports, are being infected at same rates, suggesting school is not the issue. I think the authors were pointing that out. Anecdotes are very good at spreading fear but hard to use as policy underpinnings.

  • How about the welfare of the teachers? How do you justify subjecting them to increased risk? How much additional compensation are you proposing for them and their families?

    Some cases of COVID19 have resulted in long-term if not permanent damage to organs and tissue. A couple of semesters of remote learning while waiting for full deployment of vaccines may not be ideal, but it won’t scar children for life.

    • Thank you, Steven! This is exactly what I was going to respond. The authors do not seemed very well informed on what school days are actually looking like with the struggle of sick kids, sick teachers and over burdened teachers “covering” for their ill co-workers. There was a much more uninterrupted focus on academic material when we were all virtual. We know it’s not our ideal choice for how to instruct our students, but kids are resilient. If we can be flexible and keep everyone healthy, our students are learning much bigger life lessons during the inconvenience.

    • No teachers are NOT at increased risk what on earth makes you say that? And if they do get infected its highly unlikely it came from the school. What planet are you on? And the damage to organs and tissue is due to the fact that the patient was likely in somewhat poor health before becoming infected. Are you not following the reports and the data? Or the science? Or your worrisome mentality? You know, fear and anxiety cause stress which puts a person at higher than otherwise risk for infection, or for any other disease or health disorder.

    • It is remarkable how willing teacher unions are to “never let a crisis go to waste” and pull their entire membership out of the “hero” category. We definitely don’t want them guarding our back in the trenches.

  • I’m in a scientist working in healthcare, and I live in a well-off suburb, and we’ve had the same experience as Jessa and Paul R – despite being told there’s little risk of transmission, and being in a ‘low-risk’ town, there are cases being diagnosed in my children’s elementary school every week – with subsequent cleanings and quarantining of children that were nearby. Similarly, despite being told that there’s little risk of children spreading it, I know at least 5 families where that has been the route of transmission – kids brought it home and spread it to the parents and their siblings. Schools aren’t going to be normal until at least a majority of adults are vaccinated and the overall incidence of new cases goes way down.

    • No kids got it elsewhere OR from home. As did parents. The school environment has been shown to be very minimally involved in any direct transmission. You know with your and other lines of thinking, anyone who goes anywhere is at risk and should stay home, right? So if you work somewhere, in order to protect others you should not go to work and earn money, your family then should starve. This logic you and others are using for not opening schools is bull and the future of students becoming happy strong confident functioning adults, unafraid of the world around them is worth nothing to you? Because that is not the kind of adults who will arise out of this madness if they are held hostage at home for much longer. Look at you!

  • Neither of you have any clue what it is like in a school building. Clearly. Universal, consistent masking … don’t make me laugh. That is NEVER going to be a thing. Not in this country with it’s entitled, know-it-all parents. I work in a school that opened for a small fraction of students and we had multiple outbreaks almost immediately. It didn’t even take a month before every cohort in the school had to remain home because they had ALL been exposed. In another school, parents KNOWINGLY sent their symptomatic, Covid positive child to school with a mask exemption. Repeatedly.

    Go back to your ivory tower and treating cancer and let the people who actually know something about working in K-12 schools make the decisions. You aren’t qualifed. At all.

    Every parent who wants their little darlings back in school should be required to get their entitled butts into those buildings and expose themselves. The only kids who should be back in school are the elementary school kids, the special Ed kids and the LD kids in self-contained classes. Everyone else is just fine. If they aren’t doing their work, then their parents should try parenting instead of whining about online learning.

    There certainly are kids who are suffering, but it isn’t Joe and Suzy Average or Jim and Peggy Exceptional. They are just fine. Some of them are even doing better remotely. No one talks about that.

    But if you, without a clue, and no expertise in either K-12 education or epidemiology are so sure you are right, volunteer to work in a school. Substitute teach every single day so that teachers can stay home if they are sick or at high risk. YOU go deal with teenagers whose parents have told them they don’t have to mask or physically distance themselves from others. YOU go expose yourselves to kids who are sent to school sick because mommy and daddy don’t want the burden of dealing with them. YOU go walk in the halls crushed in like a sardine being breathed on and coughed on while trying to get to your next classroom. Put up or shut up, gentlemen.

    • Wow. As a fan of the authors, I will admit I was buying the science as presented. But you provide a wonderfully written and persuasive argument. The truth may be somewhere in the middle. And I’ll admit I’d love to see these docs take a shift working in the halls of our schools.

    • Well said. When our area of 150,000 tried reopening schools late in the fall / early winter as numbers were climbing it was like playing a game of whack-a-mole. School is open. Nope, wait, closed for cleaning. Open again. Nope, gotta close for more cases. LARGELY INO BECAUSE THEY ALLOWED FULL CONTACT ATHLETICS TO PROCEED. It does not take a rocket scientist to understand that full contact sports would EASILY allow spread among students. The authors can argue all they want about there not being evidence that schools added to community spread, but just try using a little common sense. Schools were an unnecessary route of transmission between students and then back into the homes.

      Three feet? We tried that early in the pandemic and it did not work remember? Full masking? VERY FEW PEOPLE AND STUDENTS ARE USING PROPERLY FITTED N-95 RESPIRATORS. The majority of people and students are using poorly fitted cloth or lesser grade medical masks that allow blow by horizontally and vertically. HENCE THE NEED FOR 6 FEET. Simple common sense folks.

      The new guidelines make perfect sense to me, especially allowing areas to decide based upon local conditions. THAT is common sense at its best.

    • So you are putting down cancer treatment? You do realize that the likelihood of dying from cancer and related ailments is certainly higher for people especially children than covid, right? Or is that disease now no longer a threat? I would be a billion dollars there are a few people out there who would disagree with you. YOU are the one in the ivory tower hiding out from life. Life is messy and dirty and full of wonder and excitement – but you deny that to anyone who wants to live and be free, especially children. You know many of them will be emotionally scarred for life due to the ridiculous approach being taken for something that only a very small % have serious consequences from. Is their well-being worth that? I would say no, and I am so thankful that my kids are already adults and MY grandkids already know better. They will be spared. Some kids already know no other life but that which is a modified prison, with limited admittance, spaced out seating, masks and closures everywhere. What kind of world do you think these kids are seeing, and they think it is completely normal! Oh what a sad sad place we have come to be in.

  • Not to beat it to death, but we really need more information on these variants before making decisions.
    I was very much in favor of reopening -it became clear by last Fall – well before Fall – that it was very safe to do so. I have never seen any clear reason the schools could not let people under around 45, with no health problems, teach in person -with students with risk factors, or, who live around people at high risk – learning from home – not perfect but a lot better than nothing.

    The teacher’s unions, I guess, vetoed it – it was never clear why- the school boards let the teacher’s unions make all the decisions in this regard, IMO.

    But, now, with the variants, it may be a different picture. It seems clear the Kent and Bristol variants are much more contagious – they may also be more dangerous for young people – so, I feel we should make conditional plans to reopen but be ready to cancel them if the data from the variants does not look good.

  • Years ago, it was commonly claimed the Detroit, US based car manufacturers put inaccurate odometers in cars, so that, for example, when you odomoeter said 3,000 miles, you had only gone maybe 2,800.
    The manufacturers benefited from this because their warranties were based on odometer mileage, as was scheduled maintenance.
    Criticism of the fact odometers were designed to read higher than actual mileage was met with the claim “The SAE has designated X revolutions of the odometers per mile as a standard to manufacture too – but we can not get an exact match of the speedometer cable revolutions with the odometer and so, the odometers read high” _ in other words, don’t blame us, blame an “industry standard” – never mind that, of course, there was no requireement whatever to build to the “industry standard” and in fact, it was made up by the car manufacturers, because SAE was really a phony organization controlled by them, and, if there had been an honest attempt at standardization, parts would be interchangeable.
    But by creating this complex smoke and mirrors situation, those actual in control had someone to point to and blame, and some gullible people believed it.
    So, now Biden is doing this with the tier system. He will say this is “following the science” – because no doubt there was at least one person with a science degree involved in making up the rules – but it’s really pretty transparent.
    At least when other high officials lied about Covid they just made stuff up, and it was obvious – I guess that is the difference between amateur citizen politicians and an insider with decades of experience.

    I am not offering an opinion on the reopening per se – I was for it until seeing the variants rise – depending on precisely how young people respond to them, we may have much more dangerous disease pretty soon -I see the claim the Kent variant is making far more young people sick in Southern England, and saw a quote from a South African official that many more young people are getting sick there. If part of the resistance of young people in the US to severe disease is due to some unidentified learned immunity, it could be some of the variants are very dangerous for them. So I think the reopening needs to be reexamined in light ot the variants – Dr. Michael Osterholm is raising this alarm, too

    • So you started out with some comparison to fictionalized data for some gain by auto manufacturers, supposedly to show how ramping up the numbers could be used to control how businesses, schools and so one respond to the numbers and when they are higher than in reality, more desired response is achieved. then you changed and succumbed to the possibility of variants being more dangerous but we don’t know that but lets be cautious anyway? Did I get that right?

      I don’t see the comparison then so you should have left the first part out. However if you ARE trying to compare, leave the last part out and I will say you probably nailed it, this response and follow the fear-inspiring leader behavior.

  • What these authors fail to include is the likelihood that the virus is airborne. True, 6ft apart would not be overly different than 3ft apart re transmission rates, because both are equally dangerous. However, given a hint to that likelihood would keep schools closed. Further, the CDC is working with trade-offs, such as the likelihood of keeping students consistently wearing masks, the correct type of masks, washing hands correctly, staying apart physically, etc. as an example, our school was a no cell phone use during class, and yet the students would brag about how they got away with it. If we can’t count on adults following guidelines during the holidays, how are we expected to believe the children will?

    • I’ve now seen many, many kids in school and camp contexts and they wind up being better about masking than adults. In general, elementary school kids have learned to follow rules (most of them arbitrary) very very well. And because they have such robust little lungs, I think it doesn’t feel as hard to breathe for them.

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