Modelling the effects of travel and cross-immunity on pandemic risk

During the 20th and early 21st centuries, the world has seen an increase in the volume of long distance travel of people and goods, partially due to the growth of the tourism industry and in agricultural trade. This could plausibly increase the risk of pandemics by allowing pathogens to travel between distant communities and cause infections in each of them. However, cross-immunity, the phenomenon whereby infection with one strain of a disease provides some level of immunity against other strains, could mean that this enhanced pathogen spread also leads to widespread immunity to further strains. This may lead to a mechanism whereby high travel rates reduce the risk of pandemics of high virulence strains of existing pathogens due to prior infections by low-virulence strains, as hypothesised by Robin Thompson and collaborators in a forthcoming paper. In my DPhil, I plan to use mathematical models of global populations of humans and other organisms to assess the conditions under which this hypothesis could hold true, and what the implications are for public health policy. In particular, I hope to shed light on whether international travel and trade increase or decrease pandemic risk, and whether novel strains of already globally common pathogens can cause high mortality pandemics.

BBSRC priority areas:
Animal health
Global Uncertainties
Agriculture and Food Security