Harvill is a faculty affiliate of Penn State’s Center for Infectious Disease Dynamics (CIDD), and much of his research is in collaboration with other CIDD scientists. The approach of these researchers, he says, is to focus on transmission of bacteria between hosts, rather than growth of bacteria within an individual host. “It doesn’t matter if there are 10 or 10 billion
bacteria in an individual host,” he explains. “More important for that pathogen’s success is whether it gets from one host to 10 other hosts, one other host, or no other host. Simply interpreting rapid growth in an individual host as more successful is counter to the fact that unconstrained
growth of any pathogen leads to rapid death of the host: When the host dies the pathogen dies with it and loses its opportunity to spread. We focus on the success of the pathogen as measured not simply by how rapidly it can grow in an individual host but how and why it moves from one host to another and therefore its success within a host population.”

While Harvill and Wolfe’s research focuses on bacteria, a few doors down another researcher, Biao He, is studying viruses, with the goal of developing new and better vaccines. “Vaccines are the most effective way to date of preventing and combating infectious disease,” he says. “Smallpox and polio are two examples of diseases that have been literally eliminated in this country because of vaccination. It’s really the key to preventing all potentially devastating infectious diseases, especially viruses.”