Up to this point, I have essentially played defense for non-pharmaceutical interventions against COVID. Yet The Great Barrington Declaration is premised not only on extolling harms, but also proposes an alternative solution called focused protection. The premise of focused protection is that you ought to direct the majority of your time, energy and resources to protecting the most vulnerable people, while allowing those at low risk to live their lives relatively unimpeded. It emphasizes the fact that COVIDâs mortality rate increases exponentially as you get older. So the idea is to spend your limited resources keeping them safe.
This plan sounds intuitively reasonable, though there are a number of problems with it. Letâs start with the fact that it has no clear timeline. The GBD notes: âWe know that all populations will eventually reach herd immunity,â with or without a vaccine. If you have a vaccine you can basically achieve some level of herd immunity within months. But because focused protection was formulated before Pfizer and Modernaâs vaccines were shown to be highly effective, its time horizon would have relied on natural infection.
This wouldnât have yielded herd immunity. Herd immunity by natural infection has quite literally never been achieved, otherwise acute infections like measlesâthe most contagious virusâwould burn themselves out. Waves travel through social networks whose structure shifts over time, limiting exposure during each but then allowing for outbreak after outbreak. We also suspected that a re-infected variant would emerge (it did). We were not sure how long immunity to this virus would last (1, 2, 3, 4 â scientific explanation). Not every healthy person would want to get infected, creating pockets of non-immune persons. And on top of that, young people tend to associate with young people. So reopening society with only them immune would leave clusters of non-immune elderly people vulnerable to outbreaks (as happens with many vaccine preventable diseases like measles & mumps despite 85%+ immunity).
Thereâs also the problem of viral mutations. I personally believe that one of the most existential risks of the pandemic has always been a mutation towards greater lethality. COVID has low selective pressure against infection fatality rate because it is most transmissible right around symptom start, and will have been transmitted long after it potentially kills you (10+ days later). We know that it primarily evolves through small mutations across large numbers of infections. This is observable in the fact that most of the major variants we faced came from areas of high transmission.
How deadly could COVID actually have become? No one has a serious answer to that question. I think the risk is low, otherwise Iâd be living in a bunker, but because the consequences of a significantly deadlier variant would be catastrophic, it calls for precaution. Even a small increase in IFR from say .2 to .3 would have meant a 50% increase in deaths worldwide. And mind you: the SARS2 spike protein is about as far genetically from SARS (14% IFR) as H1N1 was from Swine Flu. Even small point mutations in coronaviruses can in some cases lead to marked increases in lethality. We have no idea if something like this was possible for SARS2 since it is exploring an evolutionary space we barely understand.
Hereâs one example of how its mutations could have been catastrophic. Virologists believe that the Omicron variant could have been present somewhere on earth somewhere since 2020. The virus broadly speaking would not have favored this form until a number of people had gained immunity. So if you imagine that we let its only exposed targets gain immunity while sheltering the elderly, it is conceivable that this hypertranmissible variant would have emerged, circumvented the immunity of the young, and then trampled our elderly population because we didnât see it coming (nor could we have stopped it if we did).
The point in my bringing up these hypotheticals is to say that controlling the virus is important in and of itself. Not just for patients but for scientists. Epidemiology relies on gradual, contextual knowledge generation. So allowing COVID to freely change its properties by reducing barriers to infection is a principally risky strategy on multiple fronts.