And the Centers for Disease Controls and Prevention weigh in

 Yes, this dropped a week ago now, and I have had a screen with about twenty tabs open on it during all of that time, but I knew this would take some time and I kept not having any. 

If you'd find a thread that starts at the beginning and tweets through, you can find mine from last Friday here. Instead of doing that here, I'm going to hit the big themes and push through what I think is probably key to know, while linking to other sources. 

The guidance is called the "Operational Strategy for Reopening Schools through Phased Mitigation" and it's that last bit, phased mitigation, where the first emphasis lies: schools are not viewed in isolation. Schools are part of communities, and communities as a whole need to be actively engaging in mitigation for in-person education to work in this country.
From the end of the opening paragraph:

To enable schools to open safely and remain open, it is important to adopt and consistently implement actions to slow the spread of SARS-CoV-2 both in schools and in the community. This means that all community members, students, families, teachers, and school staff should take actions to protect themselves and others where they live, work, learn, and play. In short, success in preventing the introduction and subsequent transmission of SARS-CoV-2 in schools is connected to and facilitated by preventing transmission in the broader community.

Note that THIS is the context in which we have been getting "schools can be open!" headlines: schools are parts of communities, and it is up to communities to slow and lower the spread of COVID. 

Now, if we were actually going to do this, we would be seeing a wave of closures of other things; we'd be shutting down indoor non-essential services, particularly in high transmission zones.

And we haven't. And this is, I fear, the main theme of the response to the CDC guidance, which is that doing it is hard and takes sacrificing other things, and people are very not happy about that. 

The recommendations themselves are in keeping with that: they are founded on community transmission and positivity rates. As the guidance says: 

Given the likely association between levels of community transmission of SARS-CoV-2 and risk of SARS-CoV-2 exposure in schools1,16,, a first step in determining when and how it is safe to reopen involves assessing the level of community transmission.

The chart for assessing risk is this: 

That is to be used with this county (yes, Massachusetts, county!) data tracker. As of the day that I am writing this, Worcester County is 155 cases per 100,000, and the test positivity rate is 2.51%, in both cases for the preceding seven days. Cases puts us in red, while test positivity rate puts us in blue; footnote 1 says we are to choose the higher of the two, so Worcester County remains in red. That is true of much of the country right now.

We use that with two charts, reassessing weekly, depending on if we have access to screening testing at schools. Most districts do not, so we use this one:

Note that every single level in every single one of these charts emphasizes the need for five layers of mitigation:

• correct masking (not optional, no age limits)
• physical distancing (the only place there are any compromises on this is if community transmission and positivity is very very low)
• handwashing and "respiratory etiquette" (and there isn't a lot on sanitizer; soap and water are better)
• cleaning and maintenance
• contact tracing, isolation, quarantine, again, without exception, outside of school, and thorough

Those are each described extensively at the link. 

If we did have screening--and note the Biden administration is expanding access to that--we would switch to this chart:

Note, thus, that the entirety of the guidance is based on the straightforward premise that if we do not have ongoing screening testing in schools, we do not know who actually has COVID, and thus we do not know how safe schools are. Contrast that with the ongoing "we have been open all year and" from some places that simply have not have testing, and thus do not in fact know what the transmission in school or from school has been. 

What does that re-assessment look like?

 If increasing trends persist in or plateau in substantial levels, school should transition to hybrid instruction. Similarly, mitigation strategies and transitions to full in-person instruction should only be relaxed or lifted after improvements are documented continuously for several weeks, such as decreasing to moderate from substantial levels.

I will also observe that sports only come back once you have both testing and lower community transmission. 

The emphasis on who is in buildings is built on two things overall:

• Those who most need it get it first. The executive summary says this: 
  
  • Schools that serve populations at risk for learning loss during virtual instruction should be prioritized for reopening and be provided the needed resources to implement mitigation.
  While it speaks here about learning loss, the guidance is very particular that schools serve many roles in communities, and those losses are why they are so important in the community's response to COVID.
  
  
  • When implementing phased mitigation in hybrid learning modes, schools should consider prioritizing in-person instruction for students with disabilities who may require special education and related services directly provided in school environments, as well as other students who may benefit from receiving essential instruction in a school setting.
    
    
• Elementary students are both in need of greater in-person instruction and are at less risk themselves from COVID. One mistake the guidance does not make--unlike other pieces we have seen--is dismissing risk to and from younger children. The phrase they use is "less likely."

Both of these are in keeping with a driving force of the guidance which is about equity. The document specifically and repeatedly notes the inequities of the impact of the pandemic; from the executive summary: 

...essential elements of school reopening plans should take into account the communities and groups that have been disproportionately affected by COVID-19 infections and severe outcomes.

And further:

Long-standing systemic health and social inequities have put many racial and ethnic minority groups at increased risk of getting sick and dying from COVID-19. People who identify as American Indian/Alaska Native, Black, and Hispanic are disproportionately affected by COVID-19; these disparities have also emerged among children11. Conditions in the places where people live, learn, work, play, and gather affect a wide range of health risks and outcomes, such as SARS-CoV-2 exposure, infection, severe illness, and death.

...certain racial and ethnic groups have borne a disproportionate burden of illness and serious outcomes from COVID-19. These health disparities are evident even among school-aged children11, suggesting that in-person instruction may pose a greater risk of COVID-19 to disproportionately affected populations.

They even note:

Studies have also highlighted racial and ethnic differences in parents’ attitudes and concerns about school reopening during COVID-19. Compared with White parents, non-White parents may be less likely to feel that schools should reopen for all students and are more concerned about adherence to mitigation strategies, schools reopening safely, their child becoming ill with COVID-19, and their child bringing home COVID-1921. Understanding racial/ethnic differences in parental attitudes and concerns about school reopening can inform communication and mitigation strategies and highlights the importance of considering risks for severe COVID-19 and family resource needs when developing options for school attendance during the COVID-19 pandemic.

Those communities get FIRST, not LAST consideration in this guidance, which is in marked contrast, of course, to much of the national dialogue, which as been driven by parents of privilege. This is about who has more often been getting sick, more often dying, AND AT THE SAME TIME has greater need for access to all services--not just education!--that come through schools.

And I'm not seeing any evidence that we're doing that, either.
But imagine if we did? Imagine if the first thing that the whole state said was: We need highest need special ed kids back. We need kids who don't have quiet places to work back. We need the kids who do better with adult guidance back in buildings.
And then we pivoted THE WHOLE STATE--businesses and families and state and local governments--on that. And we put THOSE kids back in buildings ACROSS THE STATE before we did anything else.

If it isn't working for Chelsea, it isn't working.

In any case...

There is also guidance here about vaccinations--not required before buildings are open, but held as highly important--and the new variants, about which they are keeping a wary eye. Even as national and state numbers are dropping, there is ongoing concerns that varieties with greater contagion levels are going to send us all backwards. 

Now, this may not sound like what you read the guidance said. To be kind, I would say that many who covered this were looking for "can schools open?" and "when?" rather than reading for more operational guidance. That is what the guidance is designed to be, however.

It does, absolutely, mean that getting every single student back in a classroom five days a week is very, very hard. Some--and I'm not going to link here; it's easy enough to find--have balked at the guidance itself there. Some of that is fair. 
At the end of the day, though, wanting anything to be 'normal' is going to take controlling the pandemic. We haven't yet. Until we do, we have work to do on that before and while we can do anything else.

And that includes schools.