Sullivan’s research is on the immunologic correlates and mechanisms of protection against infection by hemorrhagic fever viruses including Ebola virus. Her work on filovirus immunology and vaccine development is widely considered as one of the very best in the field despite the difficulties of conducting research under highly specialized BSL-4 containment conditions. Sullivan’s innovative and specialized work on filovirus immunology is recognized worldwide and has consistently been the source of novel observations that have contributed to critical advancements in the field.