Routine childhood vaccination programme coverage, El Salvador, 2011-In search of timeliness

Abstract

While assessing immunization programmes, not only vaccination coverage is important, but also timely receipt of vaccines. We estimated both vaccination coverage and timeliness, as well as reasons for non-vaccination, and identified predictors of delayed or missed vaccination, for vaccines of the first two years of age, in El Salvador. We conducted a cluster survey among children aged 23-59 months. Caregivers were interviewed about the child immunization status and their attitudes towards immunization. Vaccination dates were obtained from children immunization cards at home or at health facilities. We referred to the 2006 vaccination schedule for children below two years: one dose of BCG (Bacillus Calmette-Guérin) at birth; rotavirus at two and four months; three doses of pentavalent - DTP (diphtheria-tetanus-pertussis), hepatitis B, and Haemophilus influenzae type b (Hib) - and of oral poliomyelitis vaccine (polio) at two, four, and six months; first MMR (measles-mumps-rubella) at 12 months; and first boosters of DTP and OPV at 18 months. Timeliness was assessed with Kaplan-Meier analysis; Cox and logistic regression were used to identify predictors of vaccination. We surveyed 2550 children. Coverage was highest for BCG (991%; 95% CI: 98.8-99.5) and lowest for rotavirus, especially second dose (86.3%; 95% CI: 84.2-88.4). The first doses of MMR and DTP had 991% (95% CI: 98.5-99.6) and 977% (95% CI: 970-985), respectively. Overall coverage was 837% (95% CI: 81.4-86.0); 96.4% (95% CI: 95.4-97.5), excluding rotavirus. However, only 26.7% (95% CI: 24.7-28.8) were vaccinated within the age interval recommended by the Expanded Programme on Immunization. Being employed and using the bus for transport to the health facility were associated with age-inappropriate vaccinations; while living in households with only two residents and in the "Paracentral", "Occidental", and "Oriental" regions was associated with age-appropriate vaccinations. Vaccination coverage was high in El Salvador, but general timeliness and rotavirus uptake could be improved.

Keywords: Coverage; El Salvador; Immunization; Predictors; Routine vaccination; Timeliness.