| Institution: | 1. Department of Global Health Studies, Northwestern University, Evanston, IL 60201, United States;2. Department of Anthropology, Northwestern University, Evanston, IL 60201, United States;3. Kenya Medical Research Institute, Nairobi, Kenya;1. Office of Infectious Diseases, Centers for Disease Control and Prevention, Atlanta, GA, United States;2. Office of Biostatistics and Epidemiology, Center for Biologics Evaluation and Research, Food and Drug Administration, Silver Spring, MD, United States;3. World Health Organization, Geneva, Switzerland;4. Erasmus University Medical Center, Rotterdam, Netherlands;1. Bandim Health Project, Indepth Network, Apartado 861, 1004 Bissau Codex, Guinea-Bissau;2. Research Center for Vitamins and Vaccines (CVIVA), Bandim Health Project, Statens Serum Institut, Artillerivej 5, 2300 Copenhagen S, Denmark;3. OPEN, Odense Patient Data Explorative Network, Odense University Hospital/Institute of Clinical Research, University of Southern Denmark, 5000 Odense C, Denmark;4. Center for Global Health, Department of Public Health, Aarhus University, 8000 Aarhus C, Denmark;1. Kintampo Health Research Center, Ghana Health Service, PO Box 200, Kintampo, Ghana;2. Kwame Nkrumah University of Science & Technology/Agogo Presbyterian Hospital, P.O. Box 27 Agogo, Asante Akyem, Ghana;3. GSK Vaccines, Avenue Fleming 20, 1300 Wavre, Belgium;4. London School of Hygiene and Tropical Medicine, UK;5. University of Health and Allied Sciences, Ho, Ghana;1. Department of Obstetrics and Gynaecology, Peking Union Medical College Hospital, Peking Union Medical College and Chinese Academy of Medical Sciences, Beijing 100730, China;2. Key Laboratory of Pathogenic Microbiology & Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China |
| Abstract: | ObjectivesThe timely receipt of the recommended vaccination regimen, i.e. vaccination maintenance, is an underexplored, but important, indicator of public health. There is currently no standardized method for quantifying cumulative vaccination maintenance, however, and no simple way to explore predictors of adherence to vaccination schedules. We therefore sought to (1) develop a Vaccination Maintenance Score (VMS) and (2) apply this score to determine the predictors of vaccination behavior among infants in western Kenya (n = 245).MethodsWomen in western Kenya were enrolled during pregnancy and surveyed repeatedly through one year postpartum. Data were collected on a range of sociodemographic and health indicators and vaccinations. For each infant, we analyzed receipt of 11 vaccines recommended by the Kenyan Ministry of Health. We operationalized VMS as the total number of vaccines received on schedule. Vaccines that were not received or received off schedule were scored 0. VMS was modeled using multivariable tobit regression models.ResultsWe found that 85.7% of infants were fully immunized, but only 42.4% had optimal VMS, i.e. scored 11. The median (IQR) VMS was 10 (3). In multivariable regression, each one-point increase in maternal quality of life score (range: 0–32) was associated with a 0.22-point increase in VMS; each additional child in the household was associated with a 0.34-point increase in VMS; and initiating breastfeeding at birth was associated a 2.01-point increase in VMS.ConclusionsCoverage of the recommended vaccinations (85.7%) was nearly twice as high as cumulative timely receipt (42.4%). The VMS satisfies a need for a location-specific but easily adaptable metric of vaccination adherence behavior. It can be used to complement traditional methods of vaccination coverage and timeliness to better understand underlying behaviors that influence vaccination events, and thereby inform interventions to improve vaccination rates and decrease the burden of vaccine-preventable disease.Clinical Trial RegistrationNCT02974972 and NCT02979418. |
