"Hot-spotting" to improve vaccine allocation by harnessing digital contact tracing technology: An application of percolation theory

PLoS One. 2021 Sep 22;16(9):e0256889. doi: 10.1371/journal.pone.0256889. eCollection 2021.

Abstract

Vaccinating individuals with more exposure to others can be disproportionately effective, in theory, but identifying these individuals is difficult and has long prevented implementation of such strategies. Here, we propose how the technology underlying digital contact tracing could be harnessed to boost vaccine coverage among these individuals. In order to assess the impact of this "hot-spotting" proposal we model the spread of disease using percolation theory, a collection of analytical techniques from statistical physics. Furthermore, we introduce a novel measure which we call the efficiency, defined as the percentage decrease in the reproduction number per percentage of the population vaccinated. We find that optimal implementations of the proposal can achieve herd immunity with as little as half as many vaccine doses as a non-targeted strategy, and is attractive even for relatively low rates of app usage.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • COVID-19 / immunology
  • COVID-19 / prevention & control*
  • COVID-19 / transmission*
  • COVID-19 Vaccines / administration & dosage*
  • Contact Tracing / instrumentation
  • Contact Tracing / statistics & numerical data*
  • Humans
  • Immunity, Herd
  • Mass Vaccination / statistics & numerical data*
  • Mobile Applications
  • Models, Statistical
  • SARS-CoV-2 / pathogenicity

Substances

  • COVID-19 Vaccines

Grants and funding

This work was supported by the NSERC COVID-19 Alliance Grant ALLRP 554380- 20 (MDP, MA, CTB) and the Ontario Ministry of Colleges and Universities COVID19 Rapid Response Grant C-299-137-BAUCH (MA, CTB). The NSERC COVID19 Alliance Grant was held in partnership with Sanofi Pasteur who made only a contribution in-kind in the form of their employee (EWT). The funders provided support in the form of salaries for authors (MDP, EWT), but did not have any additional role in the study design, data collection and analysis, decision to publish, or preparation of the manuscript. The specific roles of these authors are articulated in the ‘author contributions’ section.