The B.1.1.7 variant takeover means we need to be more aware of the things that keep us safe (vaccination, distance, air flow, masks, hygiene). But the math in our title this week is a bit ridiculous, which is the point: don’t get too distracted by the news around school guidelines for separation between students, and whether it should be 6 feet or 3 feet. This study shows no meaningful difference in schools, which is what we would expect: First, in real life the separation between kids in school is functionally unrelated to policy (the study did not look at actual behaviors in schools; rather, it was based on the physical separation school districts recommended). Second, from a biological perspective, for aerosol transmission the difference between 6 and 3 feet is negligible.
Nonetheless, this is important for schools: trying to set up 6 feet of separation can be prohibitively difficult in some cases, and getting back to that real-life-with-kids concept, enforcing separation is likely impossible. But the discussion around this risks drowning out much more important topics. The key issue is that 6 vs 3 feet is the wrong question, being asked at the wrong time, when B.1.1.7 is starting to increase among some younger populations. Here’s a quick breakdown of the situation:
Discussions focused on distance alone make little sense. Beyond vaccination, the sweet spot for safety is where distance, fresh air, and masks overlap. Time is also important, with risk of transmission increasing with the amount of time spent in a potential exposure scenario. Infection = Exposure x Time.
In a classroom where kids also have snack time and lunch (no masks), critical factors are more likely to be fresh air and time. The emphasis on ventilation systems (which can be as simple as opening windows) and reducing time in the classroom has never seemed to get as much traction as issues like 6 vs 3 feet and hand hygiene.
B.1.1.7 is behaving differently among kids compared to prior outbreaks. Some activities that seemed relatively safe previously are now showing particular vulnerability to the spread of B.1.1.7. We remain hopeful that the B.1.1.7 takeover will be a “bloodless coup.” But now we may need to consider a new scenario, where for the first time we see epidemic curves for children pull away from the overall community, and perhaps rise more rapidly than adults, especially as vaccination coverage for adults continues to expand.
Community immunity is not going to help children in the near term: until vaccines receive emergency authorization for use under 16 years old, COVID transmission risk will only increase with B.1.1.7 until population-level immunity is achieved; and it is possible, considering that children are 25% of the population in the U.S. and the community immunity threshold may increase well beyond 75% with more transmissible variants, that spread will continue until vaccination is available for the entire population with no age restrictions.
B.1.17 is not only more transmissible; it causes more severe disease and death among adults. While there is little published information on pediatric impact, a quick scan of data from England shows that children were not spared from increased rates of severe disease and hospitalization, although they remained a small fraction of the overall number of hospitalizations, which continued to primarily impact older adults.
We need to look past 6 vs 3 feet and focus on what is going to allow us to keep kids safely in school, and continue in-person classes as we gradually move towards (relative) normalcy in coming months. School districts and public health leaders can take advantage of a shift in distancing policy: acknowledging that 6 feet of separation is not feasible and has not been happening in real life in most places, and in turn emphasizing that the meaningful change that needs to happen in schools right now is focus on air, masks, and time until we’re over the B.1.1.7 surge.
Air: Circulation and fresh air remain critically important. While there is no uncertainty in this, it does not appear to be prioritized from the top down, nor taken seriously at the level of individual schools. A paradigm shift in ventilation is needed, but while we’re waiting: open windows still help. Ask your kids if the windows are usually open in their classroom; if not, ask your principal or facilities manager the number of air exchanges per hour being achieved through ventilation systems. We believe that in most cases you will find a situation falling far short of best practices.
Masks: Using the right masks, correctly and consistently, remains a foundational principle in COVID control. Again, this is an area where implementation with fidelity is falling short in many places. Teachers may not want to be the nose-slip police, and kids may be arriving at school with masks that use inadequate materials or have poor fit. This remains so important that we’ll again propose distribution of masks in school. This effort can also underscore the importance of masks and trigger campaigns across school districts, working appropriately with school principals and staff, to make sure masks are being worn correctly.
Time: Like the distance equation, there is no precise cutoff (e.g. 15 minutes) that draws a line between more and less risky exposures. But time, as mentioned above, is a key factor. This is another area where renewed attention, and dedication among school district and facility leadership, will help offset the increasing risks presented by B.1.1.7.
Hygiene: While the theoretical risk of fomite transmission remains, it has not proven to be a driver of COVID. Current practices can continue, while additional strengthening is not likely needed.
What has kept our kids relatively safe until now may be inadequate as B.1.1.7 takes over. Adherence to best practices with air, masks, and time are not tasks or interventions that require any pulling back from the progress we’ve made in getting kids back into classrooms. But they are important to keeping them there safely.
P.S. We’re taking a few weeks off and will be back on the blog in April. In the meantime, we’re hoping that the New York Times will be publishing a letter to the editor that we sent in, responding to this article:
Public health leaders across the Seattle metropolitan area, and at the state level in Washington, have indeed set an example that other cities and states should follow. This should not provide cover for your newspaper to whitewash success: COVID death rates for Black and Hispanic / Latino communities exceed those of white populations in the cities held up for comparison. This is not an issue specific to Seattle, but it is one that needs to be recognized: success is relative, and it has been reserved preferentially for white populations. Unbelievably, there is not a single mention of race or ethnicity in this article. In its place, coded language: “a healthy population living in small households and a lot of workers able to do their jobs from home” refers to white people; “In the more rural areas east of the Cascades, the virus spread among farmworkers” refers to the Hispanic or Latino population, which is indeed more than five times larger in Yakima County than King County. It is shocking to see this disregard neatly tied up, again with no mention of race or ethnicity: “Yakima County’s death rate to more than double that of King County, which includes Seattle, although Yakima County’s numbers were about on par with death rates seen in many other states.” Understanding success, and acknowledging our challenges, is critical for equity in public health.