Joseph G. Allen is an associate professor and director of the Healthy Buildings program at Harvard University’s T.H. Chan School of Public Health. He co-wrote “Healthy Buildings: How Indoor Spaces Drive Performance and Productivity.”
That’s no longer the case. To think otherwise is to ignore the unmistakable signs that the vaccines are rapidly and dramatically reducing risk for all in the United States.
Many who argue for continued indoor masking point to the fact that about two-thirds of the population still isn’t fully vaccinated. It’s technically true but also misleading.
First, kids are at very low risk from covid-19, so the more relevant number for understanding population risk is that 47 percent of adults are fully vaccinated.
But that’s not the full story, either. Pfizer’s clinical trial showed that its vaccine offered 80 percent protection 14 days after the first dose. So as far as vaccines go, we should be focusing on the percentage of adults with at least one shot when we evaluate risk trends. That number is 60 percent, and seven states are already more than 70 percent.
There’s more. Something that often gets entirely ignored is that, in the United States, an estimated 120 million Americans were naturally infected as of the end of January (at great, avoidable and unnecessary cost of human lives and suffering). Natural infection doesn’t provide the full protection that vaccination does, but it does offer protection, as the very low reinfection rate shows.
Of course, the population of people who have received at least one shot and those who were infected naturally overlap, but we’ll never know by how much. But we also don’t need to know this number exactly because community-spread metrics in highly vaccinated countries prove that the combination of the two is enough to drive down cases quickly.
When countries such as Britain and Israel reached a 40 percent single-dose vaccination rate, case counts plummeted. It wasn’t because 40 percent was the unknowable herd immunity threshold; it was because that rate plus natural infection was enough to start severely reducing the number of susceptible people out there.
The most beautiful aspect of the vaccines is that they help protect even those who aren’t vaccinated, or can’t get vaccinated, such as the immune-compromised and young kids. The best evidence here is that cases among kids in Israel matched the drop in cases in adults, even though kids weren’t vaccinated.
This new phase means the United States needs to move from a top-down, one-size-fits-all approach led by the CDC to one led by local officials. To see why, it’s worth revisiting what happened with the CDC’s changing guidance on the risk from surface transmission.
By fall, the scientific evidence was clear that the risk from surface transmission was extremely low, yet the CDC still emphasized “enhanced cleaning.” This put companies in a bind. It made no sense to continue with intensive disinfecting in most places. But top-down guidance coming from CDC gave them no flexibility to make reasonable, science-based decisions on surface cleaning. They were subjected to the same rigorous disinfecting rules as hospitals.
That changed in April when the CDC finally updated its guidance so that organizations were free to develop surface-cleaning plans that were tailored to their risk level and risk tolerance. Some adopted once-a-day cleaning; others kept their deep-cleaning protocols, which is their prerogative.
The parallels to indoor masking are clear. Top-down guidance offers no flexibility, as is needed at this point in the United States. The CDC’s new update recognizes that decisions are rightly shifting to the local level and individual organizations. Some, such as Walmart and Starbucks, have chosen to relax mask requirements for vaccinated employees and customers. This doesn’t mean organizations are not allowed to require masks. The challenge, of course, is that there is no way to verify who has been vaccinated yet. For this reason, many places should still require masks indoors through July 4, as I wrote recently.
In any event, the issue is not whether the CDC was right to relax guidelines. In doing so, the agency was following the science — which shows that those who are vaccinated are at low risk of contracting or spreading the virus. The issue now is how companies and states respond.
The signs are indisputable; the vaccines are having an extraordinary effect. The daily death rate is currently about 1 in 1 million people, and, remember, deaths lag cases by three or four weeks. Cases have already dropped in the past month, so that means the death count will only continue to improve. And, on top of that, we’re still vaccinating millions per day. In fact, things are improving so quickly that the CDC’s announcement this past week on ending mask mandates that seemed so controversial will look obvious in just a few weeks’ time.