A mathematical model reveals the influence of population heterogeneity on herd immunity to SARS-CoV-2
Tom Britton1, Frank Ball2, Pieter Trapman3
- Department of Mathematics, Stockholm University, Stockholm, Sweden. tom.britton@math.su.se.
- School of Mathematical Sciences, University of Nottingham, Nottingham, UK.
- Department of Mathematics, Stockholm University, Stockholm, Sweden.
Abstract
Despite various levels of preventive measures, in 2020, many countries have suffered severely from the coronavirus disease 2019 (COVID-19) pandemic caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus. Using a model, we show that population heterogeneity can affect disease-induced immunity considerably because the proportion of infected individuals in groups with the highest contact rates is greater than that in groups with low contact rates. We estimate that if R 0 = 2.5 in an age-structured community with mixing rates fitted to social activity, then the disease-induced herd immunity level can be ~43%, which is substantially less than the classical herd immunity level of 60% obtained through homogeneous immunization of the population. Our estimates should be interpreted as an illustration of how population heterogeneity affects herd immunity rather than as an exact value or even a best estimate.
Presented By Tom Britton | ORCID iD