Where’s the Science Behind CDC’s 6-Foot Social-Distance Decree?

The new limit for schools is 3 feet. But the public is in the dark about the basis of these recommendations

By Scott Gottlieb. Excerpt:

"More distance is always better when it comes to contagion. But the 6-foot directive might have been the single costliest measure CDC has recommended, which have been largely followed over the past year. So what science went into making—and, more important, sustaining—the recommendation?

Nobody knows for sure. Most agree the guideline derives from a belief that Covid is largely spread through respiratory droplets, like flu. Old studies suggest that larger respiratory droplets are unlikely to travel more than 6 feet, and therefore close contact with an infected person is the primary mode of exposure. This research was hardly conclusive, but by most accounts it formed the basis for the initial Covid recommendations. More-recent research shows that the novel coronavirus can also spread through airborne particles, known as aerosols, especially indoors.

Most planning for a pandemic prepared for a bad flu outbreak. Given how little was known about Covid, it was reasonable to base early assumptions on the flu blueprint. But this doctrine wasn’t revisited as more data became available about the novel coronavirus. The reliance on a flu model caused public-health authorities to underestimate and overestimate Covid in important ways.

They overestimated the role of contaminated surfaces. Some Americans are still wiping down their groceries before bringing them inside. One consequence is that we were slow to recognize the extent of asymptomatic spread. The effort dedicated to scrubbing surfaces wasn’t spent improving air ventilation and filtration, which would have had a greater effect. On the other hand, because of the assumption that Covid spread primarily through droplets and not through smaller aerosols, we underestimated the protective role of wearing high-quality masks.

Experts were trying to protect Americans, and we can’t blame them for being wrong in the absence of good information. The question is whether there is an effective process for establishing these measures and re-evaluating them as new information emerges. Science isn’t a set of unchanging truths handed down by a government agency."