1. Department of Obstetrics & Gynecology; Temple University; Philadelphia PA
2. Department of Public Health; Temple University; Philadelphia PA
3. School of Nursing; University of Pennsylvania; Philadelphia PA
4. Perelman School of Medicine; University of Pennsylvania; Philadelphia PA
5. Department of Epidemiology Graduate School of Public Health; University of Pittsburgh; Pittsburgh PA
6. Vaccine and Infectious Disease Division; Fred Hutchinson Cancer Research Center; Seattle WA