How host mobility patterns shape antigenic escape during viral-immune co-evolution

TL;DR

This paper investigates how host mobility influences viral antigenic escape and survival, revealing that intermediate migration rates enhance viral persistence while highly connected networks reduce it, with implications for human travel.

Contribution

The study models the combined effects of host migration and antigenic escape on viral survival, highlighting the impact of migration rates and network connectivity.

Findings

Intermediate host mobility increases viral survival probability.

Highly connected migratory networks decrease viral persistence.

Current human migration rates may favor viral survival.

Abstract

Viruses like influenza have long coevolved with host immune systems, gradually shaping the evolutionary trajectory of these pathogens. Host immune systems develop immunity against circulating strains, which in turn avoid extinction by exploiting antigenic escape mutations that render new strains immune from existing antibodies in the host population. Infected hosts are also mobile, which can spread the virus to regions without developed host immunity, offering additional reservoirs for viral growth. While the effects of migration on long term stability have been investigated, we know little about how antigenic escape coupled with migration changes the survival and spread of emerging viruses. By considering the two processes on equal footing, we show that on short timescales an intermediate host mobility rate increases the survival probability of the virus through antigenic escape. We show that more strongly connected migratory networks decrease the survival probability of the virus. Using data from high traffic airports we argue that current human migration rates are beneficial for viral survival.