Rensimer Risk-Managed Natural Solution for COVID-19 Pandemic


This past week the COVID-19 Response Team at the Imperial College London, collaborating with the WHO Collaborating Centre for Infectious Disease Modelling, MRC Centre for Global Infectious Disease Analysis, and Abdul Latif Janeel Institute for Disease and Emergency Analytics published a critical report, “Impact of Non-Pharmaceutical Interventions (NPIs) to Reduce COVID-19 Mortality and Healthcare Demand.” With the deluge of information hourly, 24/7, this is, in my opinion, the most critically important information other than that pertaining to the SARS-CoV-2 virus itself and its behavior biologically and societally. These groups took basic information from epidemics worldwide on timelines of the disease, mortality rates, viral transmissibility and doubling time, as well as healthcare system data on capacity to meet exponential growth of cases. From those data,  they ran computer simulations to project the effectiveness of NPIs (social distancing, isolation, quarantine, and lock-down of public venues and workplaces) in diminishing and containing COVID-19 in the short-term as well as into the months ahead when, for practical reasons, such interventions would need to be relaxed or stopped. At this point in the U.S. of NPIs now descending on the populace and feeling the profound effects on our usual routines as well as a building anxiety over how we will sustain financially, this study could not be more timely and needed. The team looked at the various NPI intervention options singly and in combination in the context of the two approaches to a pandemic,

Suppression: the goal is cessation of new disease, stopping it.

Mitigation: the goal is blunting the exponential trajectory of new cases such that the straight-up curve is bent horizontally, ultimately downward toward no new cases. Mitigation is controlled occurrence of new cases to try to match case volume to healthcare resources, such as general hospital and ICU beds and staffing to achieve optimal survival numbers. The goal is management of the epidemic to spread it out over time, but not immediately ending it.

Both approaches have their problems. All out suppression may kill the epidemic, but also the “economic and societal patient” with the cure. If it continues for more than a couple weeks, the damage to people’s lives may be devastating and irreversible , for at least a long foreseeable future. Small businesses are 99% of business enterprises in the U.S., and many of these would shutter permanently if not operating for a month. COVID-19 causes literal death in probably 1% of cases (this figure subject to change with broader virus testing). However, the loss of a business, a home, retirement savings, a career path, and so on, is a virtual or figurative death. Furthermore, such disruption or even destruction of our American societal model is a national security matter. If a substantial segment of the tax base (the middle-class) is out of work and now financial entitlement dependent, there is no revenue coming into the treasury to support the military, Social Security, Medicare… you get it.

All of this is, besides the concern over becoming seriously ill, foremost on the minds of every U.S. citizen. How long can we do this? What will happen to my life and my family when the money runs out? Of course, government leaders are sending the message of reassurance and optimism of the capability of U.S. expertise and power and spirit- they must avoid panic, hysteria, and anarchy. But, this study of epidemic simulation gives information and insight on where current actions may and likely will lead, and what might best work.

Knowing the facts can be dispiriting, but I have always found it best to know as much as possible to get the best possible outcome, given the situation. It may not be the outcome we would wish, but it is the best that could have been achieved. That is the definition of optimism; confidence in achieving the best outcome in the circumstance.

Looking over these data, I have reached a conclusion that I have seen nowhere else. A number of facts support it as the solution to this pandemic, which I will detail further on. The solution is a new goal- deliberate herd immunity (DHI). This goal embraces suppression and mitigation strategies in a hybrid model, and uses NPIs in a timed way to preserve the foundations of our economy and society while managing the ongoing contagion.

In a word, the concept of DHI is to use SARS-CoV-2 virus as the vaccine. Use the virus against itself. Our problem (as is, by definition, the case with pandemics) is this is a “novel” virus- one to which the human race had not been previously exposed. So, there is no immunity worldwide to it. Once we get through this initial epidemic, it will no longer be “novel”. Most will have survived (about 99%, by current figures), and, though there will likely be future uprisings of SARS-CoV-2 again, those events will be more like seasonal influenza outbreaks. Ultimately, unless the virus has the ability to re-mix and mutate its genetic structure, like flu does, it may die out altogether, as did the original SARS virus from 2002-2003.

How do we get there? We take certain facts,

  1. NPIs work.
  2. Respiratory viruses likely generate protective or partial immunity (against future infection) in the great majority of immune-competent people.
  3. The most at-risk portion of our American population for serious illness or death is identifiable and a minority of the population.
  4. Most of our population that will survive a COVID-19 illness (Mortality Figures: 15-44yrs, 0.5-1.3%; 45-64yrs, 0.2-1.1%; over 64yrs, 1.5-4.7%) are the most socially interactive, productive, and biologically young: students, workers, small business owners. In fact, in this group, many of the infections might be trivial illness or asymptomatic.

So, the premise is simple, but somewhat counter-intuitive and “outside the box.” Why? We impulsively react to unknown or ill-defined risk and potential illness and loss of life by running from it. What I am suggesting is that, in a deliberately constructed plan, we run toward SARS-CoV-2. Embrace it so that it passages through the majority of our low-risk population while they are at school, at work, conducting their lives. Once a majority of the society is immunized (the “herd”), the virus has very few places to go and so the risk of the virus to the high-risk minority is less. If 70% of 238 million Americans are infected (Germany recently estimated that number for its country), a 1% mortality rate translates into 1.65- 2.2 million deaths; 1.65 million directly from the virus, the rest from non-COVID-19 collateral damage deaths because of unavailable care for people in otherwise dire straits- acute congestive heart failure, evolving strokes, other life- threatening infections, multiple trauma injuries, etc.

But, if you can immunize with the virus the 84% of the population under 65 yrs-old, then the remainder is 52 million people; 1% of that group infected is 520,000 deaths (compared to 1.65-2.2 million). DHI would be effective.

What about a vaccine? That has been incessantly offered as a point of hope. Well, we had two serious coronavirus family outbreaks, SARS in 2002 and MERS in 2013, with no vaccine for either yet. Other coronaviruses cause 10-30% of “head colds” – no vaccine. There would be billions of dollars marketplace for a vaccine for other viral infections such as Herpes simplex, HIV, hepatitis C, West Nile virus. No Vaccines.

Why? Because the biology of viruses is complex in the way specific virus interact with and enter human cells and then disable them. And the immunology, or the way a person’s immune system deals with a specific virus is complex and varied. There is not a uniform rule applying to all viruses. Each is its own particular complex biological model. So, though nothing is impossible, it is not reasonable to count on a safe, effective vaccine for SARS-CoV-2 in 1-2 years, if ever. That is not a strategy for the moment, when states are starting, behind closed doors, to lay down guidelines for physicians in allocating the limited number of ventilators to those with the best chance of surviving to a meaningful life- rationing as in a forward combat position. Who lives, who dies, as a decision. That has already been in operation in Italy. Bold, innovative ideas need to be put forward now to change the direction of this public health disaster in real-time.

And, the answer is in front of us. Let nature take its course. Run toward the virus in a planned and tightly controlled way.

Finally, before outlining my plan, I want to put down the salient facts from the Imperial College COVID-19 Response Team’s report.

  1. Mitigation
  2. Home isolation of suspect cases
  3. Home quarantine of those living in the same household as suspect cases
  4. Social distancing of those at most risk for severe illness/death
  5. Suppression: All those items under “Mitigation” plus,
  6. Social distancing the entire population
  7. Public venue lock-down; schools, universities, workplaces, restaurants/ bars, sports/ entertainment, public transportation.
  8. Optimal mitigation policy might reduce peak healthcare demand by 2/3 and deaths by ½.
  9. However, hospitals would still be overwhelmed and lead to rationing.
  10. Major challenge of suppression is that it needs to be maintained until and if a vaccine becomes available because, by keeping people cloistered, you do not build herd immunity on a broad scale (only limited scale as the virus maintains activity at a lower level)- so COVID-19 would likely quickly rebound when suppression NPI is relaxed. This happened with the 1918-1919 H1N1 Spanish Influenza Pandemic that killed 50 million worldwide, 675,000 in the U.S. (5-10% of world’s population then).
  11. Mitigation can never completely protect those at high-risk from severe disease or death, but many of those would likely have succumbed anyway. You are trading off that reality for a preserved social and economic order. It sounds cold, but an apt analogy is war. We have conscripted young men to send off to battle, accepting that many will never return. This is done when the country is at stake. This is no different. This is war.
  12.  SARS-CoV-2 Transmission,

1/3 = Household (80%, in China)

1/3 = Schools/Workplaces

1/3 = Community (restaurants, churches, shopping, entertainment, etc)

  • Flu Watch cohort study suggests re-infection with same strain of seasonal coronavirus highly unlikely the same or following season; suggests lasting immunity.
  • 30% of those hospitalized require ICU; 50% of those will die.
  • With no NPIs, peak group mortality will occur at 3 months.
  • With an uncontrolled U.S. epidemic, ICU bed capacity would be exceeded by the 2nd week of April- with an eventual critical care bed demand over 30x the maximum supply.
  • “optimal mitigation” applied over 3 months would still result in 8x higher peak demand above available surge capacity.
  1. Cessation of mass gatherings have little impact on rate of spread because of relatively little interpersonal contact time compared to contact time at home, schools, restaurants/bars, and workplaces.
  2. Greatest impact on virus spread is,

– Social distancing entire population

– COVID-19 test positive case isolation

– Household quarantine (entire separation of risk/exposed from others in the home)

– School closure

  1. The more successful any NPI strategy temporarily, the larger the later resurgence of epidemics if there is no vaccine or build-up of herd-immunity.
  2. NPIs may need to go on for many months.
  3. NPIs are best triggered early in the epidemic (the majority of 2 years for schools, per the simulation model, hopefully awaiting a vaccine, or building herd immunity).
  4. As total case numbers change, some NPIs might be relaxed or resumed/ increased a bit using numbers of deaths and ICU cases to trigger such moves.
  5. School/ university closure is more effective than mitigation.

So, how is all of this put together in a few strategic principles to guide policy?

  1. Herd immunity is the answer to balancing the risk of disease/death versus the economic and societal interests of the country and its citizens.
  2. Carving out high-risk groups for intensive suppression measures (long-term)
  3. Mitigation measures to be enacted and then managed to re-introduce low-risk individuals back into SARS-CoV-2 exposure to promote infection and herd immunity (DHI).
  4. Monitoring for changes in the virus that might change who is in a high-risk group by the appearance of new, outlier cases or a major increase in cases, and adjust NPIs accordingly (to account for emergent viral mutation)

The Plan

  • Complete Suppression (early in epidemic to decrease chance of healthcare system overload)
  • 2 weeks across the society (the incubation period of the virus)
  • 4 weeks for those who can sustain it economically
  • Mitigation
  • 3-5 months
  • Return to school/universities in 2-4 weeks
  • Return to work in 2-4 weeks (unless able to substantially work at home)
  • Public venues (restaurants, small business, entertainment) open in 2 weeks
  • High-Risk Group Carve Out (65 yrs and older, serious pre-existing medical conditions, and immune-deficient individuals)
  • Strict suppression NPI until epidemic gone.
  • Organized supportive services to elderly (≥65 yrs old) by family, social services organizations, churches, etc.
  • Telemedicine virtual visits with treating physicians
  • Pharmacies providing extended prescriptions of maintenance medicines and home delivery service
  • Only the elderly with critical jobs, such as healthcare professionals should be exempt.
  • Shut-down of mass transit for the foreseeable future (until a clear change in the new case curve downward), accounting for the risk of social crowding and picking up the virus from contaminated surfaces.
  • Healthcare System Suppression: currently measures to control the virus in even major urban medical center hospitals are cosmetic and inadequate. Taking the temperature on arrival of staff and visitors for entry is worthless. Most people coming to a hospital are feeling well, or likely would not go there. All infections cause fever 1-4 times per 24 hours, each in a short period of time. So, a spot temperature reading has no value as a screen for entry. Yet, both hospitals and immigration officials at airports are doing this; suggesting fundamental ignorance of infections or a deliberate “window-dressing” attempt that something is being done. The government needs to impose strict directives on hospitals as follow,
  • No visitation
  • All hospital professional and support staff screened for SARS-CoV-2 every 2 weeks as a condition for work-fitness (not currently being done);
  • Strict mitigation procedures by all hospital professional staff and support workers, not just those attending infected patients in isolation rooms. Masks, handwashing, social distancing. (not currently being done)

Understand this, the healthcare system, its workers and facilities, is the epicenter for the spread of SARS-CoV-2. These workers currently come to their shifts, physically handle the sickest in our society, and then go home to their families. In the hospitals I have been in recently, the staff are going about their duties with no change in behavior anywhere close to what the general population is doing. It is as though they think there is a special exemption from SARS-CoV-2 once you enter a medical building. I suspect they rely on hospital leadership to adequately supervise infection control measures. The government needs to focus its most intense efforts on providing personal protection equipment and mitigation rules of conduct across the profession, inpatient and outpatient. The healthcare system should be the role model for the broader society. It is where the rubber meets the road in a pandemic.

  • Pregnancy: For now, there is no definitive information on SARS-CoV-2 and a fetus. Until more science is developed, it would be better to practice contraception until the pandemic is behind us.
  • Post-Illness Isolation: 2-4 weeks, with 2 negative tests to assure virus is gone.


This proposal puts a suppression hard brake on contagion, and then the mitigation phase carves-out the high-risk groups as a special circumstance, and then returns the majority of active, productive people to their lives to pass the virus through the population to self-vaccinate with the virus. If herd immunity becomes widespread and endures, new cases and deaths will decline, probably over 3-6 months. Counting on a vaccine is unreasonable.

Be clear, the deliberate herd immunity premise has risks and unknowns. It is not certain that SARS-CoV-2 infection generates enduring immunity. However, the original SARS virus appeared to have provided immunity for at least 2 years in immune-competent individuals, and it is reasonable to assume it is analogous to COVID-19. Mortality rates below 65 yrs-old appear to be 0.2-1.3%, down to 10yrs-old, below which there have been no deaths after a worldwide total of 375,000 diagnosed cases. And those numbers will come down once we have testing to enumerate all those with modest or no symptoms who have not yet been measured. The death rate in those under 65 yrs-old might approach the 0.1% rate of seasonal flu- a reasonable trade-off for not destroying our country’s economy. Asking the American people, most especially the elderly, to put their lives at risk to save the country is no different than the sacrifice we ask of our young military in wartime, except that those at the most risk from COVID-19 have lived the majority of their lives and are focused on their legacies- their families coming up behind them. And their risk is likely about 1% for death, probably far less than that of a 20 year-old serviceman going to another type of war. I think there would be unanimous consensus by the American people, especially the elderly, that this is the right thing, the way to go.

If enduring herd immunity does not result from the experiment, what have we lost? But, we may have reclaimed our lives and the future of our country. A collateral benefit is if we do succeed at mass immunization, pooled serum collections from those recovered may give another weapon against COVID-19 illness- concentrated anti- SARS-CoV-2 antibodies for infusion.

This approach is a rational process of using the power of information to manage the pandemic, but also to the long-term critical foundations and interests of the country, and so of each of us.

Edward R. Rensimer, MD

Infectious Diseases

Director, International Medicine Center

Houston, TX

Copyright, 2020, E. Rensimer, MD, All Rights Reserved