Immunization coverage of children aged 24-35 months in the Islamic Republic of Iran: a national cluster coverage survey.

Background: Although vaccination coverage against a disease is not exactly the same as community immunity against that disease, it is undoubtedly directly related to it and provides an estimate of the coherence and efficacy of community health infrastructure.

Aims: To evaluate the vaccination coverage of children throughout the Islamic Republic of Iran in 2019.

Methods: This was a cross-sectional study. A probability proportional to size cluster sampling method was used and the vaccination data of 8682 children aged 24-35 months were collected in the form of 1447 clusters, each comprising six participants. Only valid data, including vaccination card or electronic health files, were used. The results were reported in the form of descriptive tables.

Results: Overall, 97.82% of Iranian participants (8068 of 8248) and 90.32% of non-Iranian participants (392 of 434) had received all essential childhood vaccination by the time of interview. In total, 93.02% of all participants had presentable vaccination cards, and the immunization history of 535 (6.16%) children was retrieved using their electronic health files. The dropout rate between receiving pentavalent vaccine 1 and pentavalent vaccine 3 was 0.01%. In 29 provinces, vaccination coverage was ≥ 95%. In the other two provinces, the figure was 93.30%.

Conclusion: Immunization coverage of children aged 24-35 months fully complied with eradication/elimination goals of vaccine-preventable diseases. In 2019, measles and rubella elimination was certified in the Islamic Republic of Iran. However, non-Iranian residents with immunization coverage < 95% constitute a high-risk group for possible outbreaks.