Monday, September 7, 2020

COVID-19: What is our endgame?

It’s very hard for a group to accomplish an objective if the objective hasn’t been made clear. I think lack of clarity about objectives explains some of the United States’ ongoing struggles to cope with the COVID-19 pandemic. Dealing with a pandemic is a group effort that requires widespread understanding and agreement about the end goal. This helps us align our expectations with reality and carry out our individual responsibilities effectively. 

In this blog post I will try to articulate as clearly as possible what I think our COVID-19 objectives are, or should be. As of this writing it’s too late for 190,000 Americans whose lives have already been lost to the deadly disease, but millions more lives still depend on our actions now. 

Objectives- 

1. Our primary objective should be to minimize loss of life. Life is the most precious thing we have, and dying before one’s time is a tragedy worth going to great lengths to prevent. Good medical care can improve survival chances among the infected by a modest amount, but preventing infections in the first place is by far the most effective way to reduce mortality. We have straightforward and effective means of preventing infections through hygienic measures, which include social distancing, personal protective equipment, testing, and contact tracing. At some point we will probably have an additional means to prevent infections- vaccines, but the infection prevention strategy can be very effective even while we lack a vaccine

This is important to note, because there is a widespread misconception that without a cure or vaccine, hygienic measures are only “delaying the inevitable.” I.e., there is a misconception that eventual infection of the entire population is unavoidable. It IS avoidable, though, and this would be obvious if we just remembered some of the basic math of epidemiology; the well-established science of how diseases spread through populations. In epidemiology, R0 is the average number of new people than an infected person spreads the infection to before he or she either dies or recovers. If R0 is more than 1, then the number of infected people in the population increases, eventually including nearly everybody. But if R0 is less than 1, the prevalence of the disease in the population dwindles, eventually to zero, and most people are never touched by the infection at all

Just as a fire deprived of access to new fuel will burn itself down to nothing, a disease deprived of access to new victims will also fizzle to nothing. This is the goal, and it has already been achieved by countries like New Zealand, which now need only remain vigilant for smoldering embers and sparks from abroad. 

How long it takes for the disease to fizzle out depends on how low we can get the R0. If the number is only slightly less than 1 then the disease still burns for a long time, but if the number is near zero the disease is rapidly extinguished and society can get back to normal promptly. There's more information on the basic math of epidemiology here- https://en.wikipedia.org/wiki/Basic_reproduction_number 

2. Our secondary objective is to minimize suffering. Sickness and the death of loved ones inflict great suffering, so our most effective measures to prevent infections (see objective #1) are also our most effective measures to minimize suffering. 

While sickness and death are the greatest causes of suffering in a pandemic, our measures to prevent infection may inflict suffering, as well. I.e., there are significant social, emotional, and economic costs to our hygienic measures. This creates a difficult situation, because in a pandemic that is being managed effectively, where hygienic measures are enforced and infections and deaths are kept low, all citizens suffer from the prevention measures while relatively few experience the actual sickness and death. Thus the cure is perceived as worse than the disease, and there is heavy pressure to relax the hygienic measures. 

The social, emotional, and economic costs to our hygienic measures should be minimized to the extent possible, but not to the extent that they increase sickness and death. Indeed there’s a dangerous trap of prematurely relaxing the hygienic measures, causing R0 to rise and the disease to spread again. This dooms us to more deaths and a more painful and prolonged period of hygienic measures than we would have had to endure if we had just stuck with the measures the first time. As they say in addiction recovery programs, “Half measures availed us nothing.” 

3. Our final objective is to extinguish the fires of COVID and prevent them from reigniting. Extinguishing the fires depends on our keeping R0 consistently below 1 for “a while” through hygienic measures. As I noted earlier, how long it takes depends on how well we adhere to the measures. If we half-ass it with weak, unenforced rules and repeated cycles of premature reopening, we could still be fighting it for years. However, if we buckle down it won’t take that long to get to the point where COVID is nearly gone and we can get back to mostly normal life. Preventing the COVID fires from reigniting will depend on watching carefully for smoldering embers within our borders (testing), and guarding against new sparks from abroad (also testing and international cooperation). The social and economic costs at that stage will be a lot less than they are now, and we can maintain them indefinitely if necessary. However, we may get a break if a safe and effective vaccine is developed and widely administered. When a majority of the population has immunity due to vaccination, it’s very hard for a disease to find susceptible victims. An immunized population is a like a wet and soggy forest, where sparks are unlikely to catch and spread. This is the good kind of “herd immunity.” I have more to say on herd immunity, though. 

WARNING- “Herd immunity” is one of the most misinterpreted things about the COVID-19. Whether or not herd immunity is a desirable outcome or a horrible outcome is totally dependent on how we GET to it. Herd immunity achieved by mass vaccination would be our absolute best outcome, minimizing loss of life and minimizing suffering by negating the need for hygienic measures. However, herd immunity achieved by mass infection would be the absolute worst outcome. To get herd immunity through mass infection would mean that everybody who COULD die of the disease WOULD die of the disease. That would be something like 1% of the population, which in a country the size of the United States (330,000,000 people) would be millions of people. 

Conclusion: 

The mass infection route to herd immunity would be an appalling folly resulting in unfathomably large numbers of deaths and untold suffering. 

A half-assed strategy of weak hygienic measures and premature reopening cycles (which seems to be our current strategy) prolongs suffering and leads to high numbers of preventable deaths; not much better than the mass infection route. 

Hygienic measures may be annoying, but they are absolutely our best route (and currently our only route, pending a vaccine) back to normal life. They will get us to a sustainable state where COVID-19 is basically gone and we’re just waiting for a vaccine to put the final nail in its coffin. So mask up, social distance, and call on your elected representatives to do what science assures us we MUST DO to squelch these deadly fires and return us to normalcy.

No comments: