The Herd Protects Its Weakest from Predators…Be the Herd.

Hint: The lions keep coming back when there are weak or exposed zebras.

by Robert Nelson, MD

It’s not an over-statement to assert that our strategy, thus far, for combating the novel coronavirus (COVID-19) has focused on preventing its spread through a variety of social distancing measures; such as shelter-at-home, work-from-home, closing large venues, prohibiting gatherings of 10 or more people, and numerous other variations of distancing.  This is in addition to identifying and protecting the most vulnerable from falling prey to complications thereof.  But the latter recommendations, although well known and often repeated, seem to have taken a back seat to a myriad of politically and socially controversial policies which have brought our collective economic and social engine to a grinding halt.

Here is the logic. By stopping the spread, then fewer contract the illness, then fewer get sick and fewer die. Who can argue with that? It all sounds perfectly reasonable. And even more reasonable if you’re fortunate enough to still be getting a pay check.

But what if containment strategies, relying on wide-spread comprehensive distancing protocols, simply delay the total number of cases and spread out the number of deaths?  There is ample evidence (data-driven, empiric and observational) to suggest that social distancing is far from an ideal strategy.

Distancing, in any viral pandemic, would certainly slow the spread of the contagion; and distancing was the basis of our initial response plan, the goal of which was to “flatten-the-curve.”  There was reasonable agreement among many experts, and based on the death and devastation we saw in Italy, that COVID cases could overwhelm the hospital systems’ ability to provide care for the sickest patients.  This was a valid concern and represented an unacceptable risk if the calculus was accurate.

But the objective was never to halt the virus. This distinction is crucial since it appears we’ve conflated distancing to include an implicit bias that it will get rid of the virus and make us all safer. Neither is likely to be true.

The goal of not overwhelming healthcare resources was met. But the fear that transformed a targeted strategy into a mantra was too hard to resist for policy makers and politicians whose instinct (or what some would call mandate) is to DO SOMETHING even if doing less is a better choice. And that same fear was soon found to be overstated.  And yet despite evidence that predictive models repeatedly over-estimated cases and fatalities even with distancing measured factored in, many have not taken their foot off the regulatory gas peddle or seriously thought of changing directions even though the evidence shows that most people are not at high risk.

This disconnect and failure to pivot, unfortunately, is more ideological than it is epistemological.  You only have to look at the accusations and insults hurled by proponents of one strategy at the proponents of another; the lack of civil discourse and failure to acknowledgement that we all want the same good outcomes, shows us how easy it is to be pulled into our ideological corners.  The data should drive the policy; not the other way around.

The implications that the real Case Fatality Rate (infection mortality rate) is likely to be much lower than we realized is vital information that should allow us to pivot very quickly. We have lost precious time arguing over the benefits of distancing and testing supplies and whether the President actually believes we should inject disinfectants.  We should have been devising reverse lock-down strategies designed to actually prevent death; death from the virus and death from other causes including unemployment and all manner of social depravity and the illnesses that come with it.

So, can a strategy based primarily on distancing accomplish the goals we all want without unacceptable human collateral damage? And is that strategy even plausible based on the behavior of contagious respiratory viruses, and specifically based what we know about SARS-CoV-2 (COVID-19)?  And furthermore, will it accomplish the goal of diminishing deaths?

To better answer those questions, let’s examine what we know about the behavior of this virus, much of it revealed fairly early in the lock-down and some of it we knew even before the lock-down began.

  • COVID-19 appears to have a very high infectivity, which means it spreads horizontally (not just close household contacts) within a population very quickly. It likely spreads quicker and easier than Influenza, which is highly contagious.
  • Aggregate data from around the world and compiled by many government agencies indicates that over 80% of cases are very mild with virtually complete recovery.
  • Anywhere from 15 – 40% may be asymptomatic
  • A look at the New York data, undeniably the epicenter in the U.S., shows…
    • risk of death in people 18 – 45 to be about 0.01% or 10 per 100,000
    • For people under age 18 years, the death rate approaches zero
    • Two-thirds of fatal cases occurred in patients over 70 years of age
      • More than 90% of those fatal cases had underlying serious illnesses
    • Even for people ages 65 to 74, only 1.7 percent were hospitalized
    • For those who don’t have serious underlying medical illness, the chance of dying from COVID-19 is very small, regardless of age and especially if under 50
    • Nearly 25% of NYC residents tested show antibody to COVID, so real number of cases could be at least 12x more than the number of confirmed cases meaning that the true case fatality rate is much lower than we thought initially
  • Herd immunity helps act a human shield, or firewall so to speak, to protect those at risk by simply cutting down on the chance they will come in contact with someone who is infected.  In the absence of a vaccine, herd immunity is the best way to protect the vulnerable and thus cut down the death rate.

Sequencing and staging a return to work & life normalcy based on risk assessment, rather than waiting on achieving some arbitrary drop in cases or death rate (which is a function of current testing limitations) is a solution which can cut down on unnecessary deaths and avoid collateral human suffering across other important dimensions.

We can start by identifying the intersections of various Venn diagrams where low risk people can return to the most essential work; and likewise identify lower risk environments where less scrutiny about risk is needed.

Interventions such as N-95 or even regular surgical masks can be used in selected situations as needed.  Staggering shifts and segregating open offices with cubicles or using room dividers can possibly minimize exposure in the workplace for those at risk.

Of course, the basics of hand-washing and proper respiratory “hygiene” are assumed to be at the forefront of any strategies.

These strategies should be done simultaneously with vigilant surveillance for new cases so appropriate measures (testing, observation, isolation or contact tracing) can be initiated.

And those at highest risk could work if they can do it safely; or they can work from home if they can for as long as possible.

Last, but certainly not least, -given that nursing home COVID cases have accounted for a disproportionate percentage of deaths- we need to segregate infected patients/residents from non-infected and have stringent protective measure for those caring for these at-risk people, just as if they were in a hospital.

If we want to get our world back, we have to get back in the world  (paraphrased from David Katz, MD)

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