Harnessing Pathogen Evolution

Infectious agents – bacteria, viruses and parasites – evolve in response to selective pressures created by our immune systems, vaccine deployment, and antimicrobial drugs. The resulting genetic changes in the pathogens often have direct consequences for human health – most prominently, antibiotic resistance, but also ongoing transmission of pathogens that have evolved to evade our natural or vaccine-induced immune responses. Understanding the mechanisms by which this selection happens offers the opportunity to control it and direct it in more benign ways. Quantifying the contribution of particular evolutionary changes to disease burden allows priority-setting for antimicrobial stewardship, vaccine deployment and other responses. Evolutionary changes in pathogen genome sequences can also be used to track transmission and inform our understanding of who infects whom. Our research in this area ranges from very basic studies of mechanisms of natural selection in pathogens through applied efforts to direct evolution in ways that will improve human health.