Two-population SIR model and strategies to reduce mortality in pandemics

TL;DR

This paper models COVID-19 spread using a two-population SIR framework, proposing strategies like phased interaction reduction and immunization of elderly hubs to effectively lower mortality rates.

Contribution

It introduces a merged SIR model with dynamic interaction strategies and highlights the importance of targeted elderly immunization for mortality reduction.

Findings

Reducing contacts delays death but doesn't significantly lower total mortality.

Phased interaction strategies can reduce final mortality.

Immunizing elderly hubs significantly decreases mortality.

Abstract

Despite many studies on the transmission mechanism of the Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), it remains still challenging to efficiently reduce mortality. In this work, we apply a two-population Susceptible-Infected-Removed (SIR) model to investigate the COVID-19 spreading when contacts between elderly and non-elderly individuals are reduced due to the high mortality risk of elderly people. We discover that the reduction of connections between two populations can delay the death curve but cannot well reduce the final mortality. We propose a merged SIR model, which advises elderly individuals to interact less with their non-elderly connections at the initial stage but interact more with their non-elderly relationships later, to reduce the final mortality. Finally, immunizing elderly hub individuals can also significantly decrease mortality.