Controlled Avalanche – A Regulated Voluntary Exposure Approach for Addressing Covid-19

  1. Eyal Klement
  2. Alon Klement
  3. David Chinitz
  4. Alon Harel
  5. Eyal Fattal
  6. Ziv Klausner

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Abstract

Background

The ongoing Covid-19 pandemic has driven many countries to take radical suppression measures. While reducing mortality, these measures result in severe economic repercussions, and inhibit the development of herd immunity. Until an effective vaccine will be available, we propose an alternative approach, akin to avalanche control at ski resorts, a practice which intentionally triggers small avalanches in order to prevent a singular catastrophic one. Its main goal is to approach herd immunity faster than the current alternatives, with lower mortality rates and lower demand for critical health-care resources. According to this approach, individuals whose probability of developing serious health conditions is low (i.e. 20-49 years old with no comorbidities) will be offered the option to be voluntarily exposed to the virus under controlled supervision, and will then be issued ‘immunity certificates’ if they are confirmed to have developed SARS-CoV-2 antibodies.

Methods

Using a compartmental model we examine the implications of the controlled avalanche (CA) strategy over the population in Israel. We compare four scenarios: in two scenarios the CA program is applied to the low-risk population (with the rest of the population subject to mitigation measures), followed by mitigation for the entire population or by uncontrolled spread. These are compared to mitigated and uncontrolled scenarios without the CA program. We discuss the economic, ethical and public health implications of the CA strategy.

Findings

We show that compared to mitigation of the entire population, the CA strategy reduces the overall mortality by 43%, reduces the maximum number of people in need for ICUs by 62% and decreases the time required for release of 50% of the low-risk population by more than 2 months.

Interpretation

This study suggests an ethically acceptable practice, that enables reaching herd immunity faster than the current alternatives, with low mortality and minimal economic damage.

Article activity feed

  1. ScreenIT

    SciScore for 10.1101/2020.04.12.20062687: (What is this?)

    Please note, not all rigor criteria are appropriate for all manuscripts.

    Table 1: Rigor

    NIH rigor criteria are not applicable to paper type.

    Table 2: Resources

    No key resources detected.

    Results from OddPub: We did not detect open data. We also did not detect open code. Researchers are encouraged to share open data when possible (see Nature blog).

    Results from LimitationRecognizer: We detected the following sentences addressing limitations in the study:
    The remaining concern is whether the state should impose a limitation on voluntary assumption of risk, due to paternalistic considerations. These considerations do establish a maximum level of risk – or maximum age, above which voluntary exposure cannot be justified. It may therefore well be that the demand for participation in the program would exceed the maximum age allowed. The implementation problem may then be how to prevent higher risk individuals from independently contracting the virus. To implement CA, governments must have the political will to commit to a program that combines isolation/closure with voluntary exposure for a pre-defined time period. Given extreme suppression measures that governments have implemented, it would seem reasonable that controlled, voluntary exposure could be managed. Rather than opening businesses and public spaces to all low risk groups, thus risking uncontrolled disease spread including to vulnerable populations, governments can leverage success in suppression policies to move to a CA program. Implementation of the program does not imply that professional personnel will infect people similar to challenge studies. Rather, the government can provide the tools and environment for whoever likes to contract infection to perform it easily and in a regulated manner. Suppression resources may be turned to enforcement of rules regarding screening of applicant volunteers, monitoring mechanisms and patterns of infection, recovery and immunity amo...

    Results from TrialIdentifier: No clinical trial numbers were referenced.

    Results from Barzooka: We did not find any issues relating to the usage of bar graphs.

    Results from JetFighter: We did not find any issues relating to colormaps.

    Results from rtransparent:
    • Thank you for including a conflict of interest statement. Authors are encouraged to include this statement when submitting to a journal.
    • Thank you for including a funding statement. Authors are encouraged to include this statement when submitting to a journal.
    • No protocol registration statement was detected.

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  2. Version published to 10.1101/2020.04.12.20062687v1 on medRxiv