1. Department of Pediatrics, Duke University, Durham, North Carolina
2. Department of Internal Medicine, Duke University, Durham, North Carolina
3. Nicholas School of the Environment, Duke University, Durham, North Carolina
4. Human Vaccine Institute, Duke University, Durham, North Carolina
5. Department of Obstetrics and Gynecology, Duke University, Durham, North Carolina
6. Department of Obstetrics and Gynecology, Warren Alpert Medical School of Brown University, Providence, Rhode Island