In 1985, his group became the first to solve the structure of an animal virus when it mapped the three-dimensional structure of a common cold virus, making it possible to study surface features and interactions of a cold virus at atomic resolution. In 1986, his team pinpointed the site in a common-cold virus where antiviral agents bind and work to prevent the virus from reproducing. Is a parasitologist. Has directed and carried out studies on the spread of Lyme disease and hantavirus through parasites carried on rodents. In 1994-95 completed a statewide survey of hantavirus carried by rodents in Indiana.
Current research involves studies of zebra mussels and round gobies in southern Lake Michigan.
Developed mathematical models of population growth and disease epidemics, especially AIDS, via computer simulations. Also is studying virus assembly to understand ways to construct a system for gene delivery for cancer therapy. Editor of international journal Seminars in Virology.