Keefer also serves as associate director of scientific administration for the international HIV Vaccine Trial Network. So far more than 900 people in the Rochester area have taken part in HIV vaccine studies, making Rochester among the top cities in the global world designed for participation in the visit a vaccine against HIV. Rochester is among only two sites worldwide that have been working on a vaccine since the first systems were created in announced it is collaborating with the University of California, Davis in the area of food safety. The research collaboration will concentrate on the advancement of a new process that can reduce the time required to identify food-borne pathogens from many days to only a few hours. This technology integrates mass-tagged PCR primers for amplification and Liquid Chromatography/Mass Spectrometery for the speedy identification of Salmonella serovar subtypes as well as other food-borne pathogens. The technology combines the specificity and sensitivity advantages of PCR, with the partial automation of LC/MS, and the sensitivity of recognition of the mass spectrometer. The mass tags are little organic molecules coupled to the PCR primers, which provide two unique identifiers per target–like a dual barcode per target.