Dr Grad's research investigates how pathogens evolve, emerge, and spread through populations, and is motivated by the need to develop new strategies to slow or contain their spread. He is establishing a diverse research program rooted in innovative genomics and statistical methods to understand the complex relationships between microbial and host populations. At a population level, by linking phylogenetic reconstruction with epidemiological and demographic data, genomic epidemiology presents the opportunity to track transmission from person to person, infer transmission patterns of pathogens and sequence elements that confer phenotypes of interest, and estimate transmission dynamics of outbreaks. At the level of the individual host, he aims to investigate how host immunity and pathogen characteristics influence pathogen evolution and clinical disease. In the near future, his work will focus on several projects that aim to advance understanding in these areas: (1) the spread of antibiotic resistant Neisseria gonorrhoeae with new and ongoing collaborations with the CDC, NYC Dept of Health and Mental Hygiene, and the Wellcome Trust Sanger Institute; (2) the within-host evolution of respiratory syncytial virus, in collaboration with the Broad Institute and the University of Tennessee Health Sciences Center; (3) the evolution of influenza and impact of influenza antigenic diversity on seasonal vaccine efficacy, in collaboration with the J. Craig Venter Institute, University of Chicago Hospital, and Stanford University Hospital; (4) mathematical models of cholera transmission, in collaboration with the WHO.