Age-appropriate versus up-to-date coverage of routine childhood vaccinations among young children in Israel

Background and aims: Routine childhood vaccinations schedules recommend that children receive the vaccine doses at specific ages. Vaccination coverage data are conventionally reported by the up-to-date method. We aimed to assess vaccination timeliness by the age-appropriate method and compare with the up-to-date vaccination coverage. Methods: Assessment of age-appropriate and up-to-date vaccination coverage among children born in Israel in 2009 and followed to age 48 months (national representative sample, n = 3892). The vaccinations included: Hepatitis B vaccine (HBV), Diphtheria-Tetanus-acellular Pertussis-Polio-Haemophilus-influenzae-b (DTaP-IPV-Hib), Pneumococcal conjugate vaccine (PCV), Measles-mumps-rubella-varicella vaccine (MMR/MMRV) and Hepatitis A vaccine (HAV). The categories defined: age-appropriate (at the recommended age and up to 1 month), delayed less than 6 months, delayed 6months and above and unvaccinated (48 months). Results: The age-specific vaccinations assessment showed considerable delay in receipt of routine vaccination. While most (96%, 95%, 91%, 96%, 94% and 86%) children were vaccinated up-to-date for HBV3, DTaP-IPV-Hib4, PCV3, MMR/MMRV1, HAV1and HAV2 vaccine doses; only 26%, 29%, 47%, 64%, 55% and 12% were vaccinated age-appropriate. Vaccination delay was more common in vaccines with multiple doses. Vaccination delay was associated with high child's birth order, low socio-economic rank, ethnicity (delay more common in Jews vs. Arabs), season of birth (winter) and delayed receipt of DTaP-IPV-Hib vaccine 1st dose. Conclusions: This study assessed age-appropriate childhood vaccination coverage in a national cohort of children. While the overall vaccination coverage stands in line with the WHO goals, vaccination timeliness and equity are inadequate and targeted public health intervention programs aimed at vaccination timeliness are necessary.