More women over 15 years of age see an obstetrician/gynecologist than any other specialist, and women are increasingly relying on obstetrician-gynecologist physicians for their primary care. However, many obstetrician-gynecologist practices do not stock and administer vaccinations, and if they do, may administer only one or a few vaccines. It is particularly important to immunize women of reproductive age, in order to protect the mother herself, the growing fetus, and neonates. While pregnant women have been considered a priority for influenza vaccination for many years, rates of influenza vaccination coverage among pregnant women are generally very low. In addition, since 2005, there are two newer vaccines available that are of major import for younger women of reproductive age, tetanus-diphtheria-acellular pertussis vaccine (Tdap) and Human Papilloma Virus vaccine (HPV). Rates for these vaccines are also very low among adults. In the current proposal, a study team with extensive experience in immunization delivery research will investigate the feasibility, effectiveness, and cost of a multi-faceted immunization program to promote vaccination within the obstetrician-gynecologist setting. The study will be conducted in obstetrician-gynecologist practices in public, private, and managed care settings, serving women of diverse socioeconomic and racial/ethnic backgrounds in rural, suburban and urban locations. Qualitative research, consisting of key informant interviews, will be conducted among providers and staff to assess the feasibility and acceptability of various practice-based strategies to promote vaccination. These qualitative data will be utilized to develop a multi-faceted immunization program. An office manager with extensive previous experience with practice-based immunization delivery will consult with the practices to address financial barriers. We will conduct a cluster randomized trial, implementing the multi-faceted immunization program in those randomized to the intervention group in order to determine the effectiveness of the program in improving immunization rates, specifically for influenza, HPV, and Tdap vaccines. The investigation will also include a cost analysis, in which we will measure the costs of developing and implementing the immunization program. Finally, we will conduct qualitative interviews with providers and staff after the implementation phase, to determine the factors that facilitate or hamper the sustainability of the program. Findings from this study will be directly relevant to Healthy People 2020 goals of reducing the number of indigenous vaccine-preventable diseases in the U.S. and will also be used to develop a vaccination implementation plan ("toolkit") to be made available to control practices and obstetrician-gynecologist practices throughout the U.S.