She is a Professor of Behavioral and Social Sciences at the Brown University School of Public Health. She holds a secondary appointment in the Division of Infectious Diseases at Brown University Medical School. She is also the Executive Director of the Rhode Island Public Health Institute (RIPHI). She conducts applied research and leads public health programs focused on enhancing health equity and reducing racial disparities.

In 2020, RIPHI launched Open Door Health, Rhode Island’s first LGBTQ. Open Door Health provides primary and sexual health care to Rhode Island’s diverse population. Open Door Health launched a new COVID-19 screening center and vaccine program in spring 2021 that continues today. In 2021, in partnership with over 40 other institutions, she launched NOURISH RI. NourishRI is a statewide advocacy campaign promoting a SNAP incentive program. This program would double the value of SNAP for Rhode Islanders when they use SNAP to purchase fruits and vegetables. A social scientist by training, Dr. Nunn has worked in several countries and conducted domestic and international research on a variety of health topics, including HIV/AIDS, access to reproductive health services, and family planning. Dr. Nunn has also conducted global health policy research that explores how politics, economics and intellectual property rights affect AIDS policy and access to medicines in developing countries.