Understanding COVID-19 spike, return of mask mandates and ‘pandemic of the unvaccinated’

In a country like the U.S., in which less than 50 percent of the population is fully vaccinated against COVID-19 and possibly 30 to 40 percent have immunity from prior infection it is not surprising that a more fit variant such as delta has led to increasing cases in most states. However, in this phase of the pandemic cases matter much less than in the past.

With prior spikes of COVID-19 activity what invariably followed a few weeks later were high levels of hospitalization and deaths. These phenomena were coupled. What the vaccine has done is decoupled them by removing the ability of the virus to cause severe disease, hospitalization, and death to the degree and at the rate it once could. This decoupling is achieved by high rates of vaccination in the highest risk population — the elderly. In the U.S., close to 80 percent of those above 65 years of age are vaccinated and this, more than anything, is responsible for the change most hospitals experienced in their COVID-19 censuses from January to July. 

However, it has become clear that decoupling is not universal across the country and looking at overall vaccination rates can obscure significant vulnerabilities. Rising cases in areas in which there is not universal vaccination of high-risk individuals of any age will translate into an uptick in hospitalization. When a significant proportion of these higher risk unvaccinated individuals lives in geographic proximity, it can strain the resources of hospitals (as appears to be the case in places like Springfield, Missouri) which, for myriad bureaucratic reasons, are always capacity constrained.

COVID-19 is, as CDC Director Dr. Rochelle Walensky stated, “a pandemic of the unvaccinated” and as the unvaccinated appear to cluster in certain regions of the country, COVID-19 has transformed from a systemic threat to a regional threat. A regional threat to hospital capacity can be managed with proactive planning and load-balancing among neighboring hospitals acting as health care coalitions.

What also makes the recent COVID-19 case increases different than in the past is that a solution is nearly ubiquitous: the vaccines. Safe and highly efficacious vaccines are in plentiful supply in this country making the entire scenario completely preventable. The COVID-19 vaccines are performing tremendously at defanging this virus and its troublesome variants. They have succeeded to such a degree that the fully vaccinated have little to fear of the delta variant.

Given vaccination rates and vaccine availability, mask mandates for the vaccinated — such as those about to be enacted by Los Angeles County — are not backed by the scientific evidence and could, paradoxically, end up stalling vaccine uptake as people will no longer see the vaccine as a way back to normalcy.

To treat the 61 percent of county residents that are fully vaccinated as if they pose the same risk as the unvaccinated is not justified and wrong. It is doubtful how well this order will be complied with, what metrics will be used to guide its recension, and what impact it will have.

When thinking about the pandemic, it is critical to realize that SARS-CoV2 is not a virus that is eliminable or eradicable. It is an efficiently transmitted respiratory virus with an animal host and it will be the fifth seasonal coronavirus that we will deal with decades into the future. While it is important to minimize cases, primarily using vaccination, they will still occur. So long as hospital capacity is not compromised, the pandemic response is succeeding.    

Amesh Adalja, M.D., is an infectious disease physician and a senior scholar at the Johns Hopkins Center for Health Security. Follow him on Twitter: @AmeshAA.