Dr. Messina is the chief of the Division of Infectious Disease at Johns Hopkins All Children's Hospital. She joined the pediatric infectious disease program in 2006. A graduate of Vanderbilt University School of Medicine, she completed her pediatric residency at University of Texas-Southwestern Medical Center/Children's Medical Center, Dallas, followed by a pediatric infectious diseases fellowship at UT/Southwestern Medical Center. She was a staff pediatrician at Children's Medical Center Dallas. In the Johns Hopkins Medicine Clinical Awards, Dr. Messina was named Johns Hopkins All Children’s Hospital physician of the year in the 2019 and led a COVID-19 Analytic Response Team that received the Armstrong Award for Excellence in Quality and Safety in 2022.