National vaccination coverage and timeliness among children born between 2018 and 2022 by analyzing national e-prescription data in Greece

Background: Monitoring childhood vaccination coverage (VC) is essential for evaluating immunization programme performance and informing public health policy. This study aimed to assess VC and timeliness among children born between 2018 and 2022 in Greece. Methods: We conducted a population-based study using dispensed vaccine e-prescriptions issued between 1/1/2018 and 31/12/2024 for children born in Greece from 2018 to 2022, identified through the National Electronic Prescription Database. VC and timeliness were estimated for all vaccines in the Greek National Immunization Program (NIP). Full VC at 24 months was defined as 4 doses of diphtheria–tetanus–acellular pertussis (DTaP), poliomyelitis (IPV) and Haemophilus influenzae type b (Hib), 3 doses of hepatitis B (HepB) and pneumococcal conjugate vaccine (PCV), and 1 dose of measles–mumps–rubella (MMR), meningococcal C (MenC) and varicella (VAR) (4:4:3:3:1:1:1 series). Children receiving no dose of any vaccine by 24 months were considered completely unvaccinated. Results: Among 400,959 children, VC at 24 months exceeded 85% but remained below 90% for all vaccines; VC for ≥4 doses of DTaP-IPV and Hib and ≥ 1 dose of VAR was 77.3%, 76.4%, and 81.5%, respectively. On-time vaccination was highest for MenC (88.4%), followed by MMR (83.9%) and VAR (80.5%), and lowest for DTaP and PCV. Full series VC at 24 months was 66.7%. Regional disparities were observed, with lower VC and timeliness in the Aegean Islands and higher in Crete and Western Macedonia. Overall, 3.1% of children were completely unvaccinated. Conclusions: Although overall VC was relatively high, important gaps in timely and complete vaccination remained, highlighting the need for targeted strategies, especially in lower-performing regions.