Background This study assessed the extent of delays in childhood vaccinations and examined sociodemographic correlates of delayed and missing vaccinations.

Methods Datasets from the 2005–7 Multiple Indicator Cluster Surveys from 31 countries were used. Information on vaccinations was based on vaccination cards. Survival analysis was applied to assess age-specific vaccination rates, and multilevel logistic regression analysis was used to assess factors associated with delayed and missing vaccinations.

Results The median vaccination coverage across all countries varied from 91% measles-containing vaccine (MCV) to 98% bacille Calmette–Guérin vaccine (BCG). The median fraction of timely administered vaccinations was 65% (range 14.5–97.2%) for BCG, 67% (11.6–89.3%) for the first dose of vaccine against diphtheria, tetanus and pertussis (DTP1), 41% (10.8–82.1%) for DTP3, 68% (29.7–90.3%) for the first dose of polio vaccine (polio1), 38% (10.5–81.0%) for polio3 and 51% (22.3–91.1%) for MCV. The median of the median delays across all countries was 2.1 weeks (IQR 0.9–3.0) for BCG, 2.4 weeks (1.5–3.1) for DTP1; 6.3 weeks (3.3–9.0) for DTP3; 2.0 weeks (1.3–3.1) for polio1, 6.6 weeks (4.3–9.3) for polio3 and 4.1 weeks (2.5–5.8) for MCV. A higher number of children in households and lower socioeconomic status were associated with delayed and missing vaccinations; however, the effects of socioeconomic gradient varied by country.

Conclusion Most countries achieved high up-to-date vaccination coverage. However, there were substantial vaccination delays. Collecting information on the timeliness of vaccination in national surveillance systems will provide a more complete view of vaccination coverage. Missing and delayed vaccinations can be addressed jointly in prevention programmes.