Factors associated with pneumococcal conjugate and rotavirus vaccines update among infants: evidence from the Africa Centre Demographic Surveillance Site, South Africa, 2008-2011.
Introduction: Despite advances in prevention and treatment of vaccine-preventable diseases, diarrhoeal and pneumococcal diseases remain a major source of morbidity and mortality among children worldwide. The introduction of vaccines has led to dramatic reductions in the burden of infectious diseases and mortality among children. South Africa was the first country in Africa to introduce rotavirus vaccine (RV) and pneumococcal conjugate vaccine (PCV) in 2008 as part of its national immunisation programme. Performance of immunization programmes is commonly measured by the coverage and uptake of vaccines, hence ensuring that every child is immunized at the earliest or appropriate age is an important public health goal. We therefore assessed proportions and factors associated with uptake of RV and PCV among infants who were followed during the routine demographic surveillance system of the Africa Centre Demographic Surveillance Area (DSA) in a rural South Africa setting. Methods: An open cohort of children resident in the DSA aged 12 months or below was prospectively followed between January 2008 and December 2011. Trained interviewers visited households and administered a standardised questionnaire. Mothers and caregivers were asked to show the interviewers the South African Road-To-Health (RTH) card for all children aged 12-23 months at the time of the visit or through maternal recall for children whose RTH card was not available. The RTH card includes dates of all routine vaccinations a child has received. Rotavirus vaccine doses are given at 6 and 14 weeks of age and PCV doses at 6 and 14 weeks and 9 months. Complete uptake was defined as “complete” if a child received all recommended doses of either RV or PCV and incomplete if a child did not receive any dose or received one dose of RV or PCV. Logistic regression models were used to assess factors associated with uptake of RV and PCV separately. Results: A total of 6,263 children were included in the analysis, of which 3,082 (49%) were females. At birth, 3,823 (61%) children were living in rural areas and about one-sixth of the children were living in households located far from a health facility (≥5km). The overall uptake of RV and PCV vaccines among children aged 12 months or below was 50% and 37% respectively. Infants who ever migrated outside the DSA had reduced odds of complete RV and PCV vaccination compared to infants who did not out migrate (adjusted OR=0.49, 95% CI 0.41-0.57) and (adjusted OR=0.52, 95% CI 0.43-0.63) respectively. Complete uptake of RV was associated with the increase in education levels of mothers compared secondary education (adjusted OR=1.70, 95 % CI 1.02-2.34) or tertiary education (adjusted OR=1.80, 95 % CI 0.97-2.44). Infants whose mothers were employed were less likely than infants whose mothers were not employed to have complete vaccination for RV or PCV (adjusted OR=0.71, 95 % CI 0.60-0.84) and (adjusted OR=0.81, 95% CI 0.68-0.96) respectively. Similarly, infants whose mothers were resident in the DSA were more likely than infants whose mothers were not resident to have complete vaccination for RV or PCV (adjusted OR=1.97, 95 % CI 1.49-2.60) and (adjusted OR=1.55, 95% CI 1.16-2.08) respectively. Conclusion and recommendation: The uptake of complete RV and PCV were generally low among children in rural South Africa within our study period. Child outmigration, maternal employment, maternal education and maternal residency in the DSA at child birth were associated with complete uptake of RV and PCV vaccines. Programmes targeting mothers of lower socio-economic status are required. Such programmes may include vaccine awareness and immunization campaigns at the community level to improve vaccine uptake and more targeted interventions in areas with low RV and PCV uptake.
infant, rotavirus, pneumococcal conjugate, vaccine uptake