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Timeliness of immunisations in preterm infants in the Netherlands
Elsbeth D M Rouers1, Guy A M Berbers2, Josephine A P van Dongen3
1Centre for Infectious Disease Control, National Institute for Public Health and the Environment, Bilthoven, the Netherlands; Julius Centre for Health Sciences and Primary Care, University Medical Centre Utrecht, Utrecht University, the Netherlands.
Insights
In the Netherlands, many preterm infants miss timely immunisations, especially those born extremely early. Lower socioeconomic status and extended hospital stays contribute to these delays, highlighting a need for targeted parental support.
Area of Science:
- Neonatal care
- Public health
- Immunology
Background:
- Preterm infants in the Netherlands receive immunisations based on chronological age, not corrected gestational age.
- This approach may lead to delayed vaccination schedules for premature infants.
Purpose of the Study:
- To assess the timeliness of routine immunisations in preterm infants within their first year of life.
- To identify factors contributing to delayed vaccinations in this population.
Main Methods:
- Prospective cohort study of preterm infants (October 2015-October 2017).
- Infants stratified by gestational age (<28, 28-32, 32-36 weeks).
- Data collected via parental questionnaires and medical records; analyzed using multivariate logistic regression.
Main Results:
- Only 60.5% of preterm infants received their first immunisation on time (42-63 days).
- Timeliness was lowest in the extremely preterm group (<28 weeks GA) at 37%.
- Low socioeconomic status and prolonged hospitalisation (>37 weeks GA) were significant predictors of delay.
Conclusions:
- Vaccination start is frequently delayed in preterm infants, with significant differences across gestational age groups.
- Lower socioeconomic status and extended hospital stays are key determinants of delayed immunisation.
- Interventions should prioritize support and counselling for parents in lower socioeconomic status groups to improve vaccination timeliness.
Background:
In the Netherlands, preterm infants receive the immunisations at the same chronological age as recommended for term infants without correction for gestational age (GA). The aim of this paper was to describe the timeliness of the routine Dutch national immunisation schedule in preterm infants in their first year of life and to evaluate possible determinants of delay.
Methods:
Preterm infants were prospectively recruited between October 2015 and October 2017 and stratified according to GA (<28, 28-32 and 32-36 weeks). Data from the baseline parental questionnaire, monthly parental questionnaires and medical records were used to determine the immunisation age and proportion of infants timely receiving the first immunisations (between 42 and 63 days). Results were compared between the GA and birth weight (BW) groups. Determinants associated with timeliness of immunisation were studied by multivariate logistic regression analysis.
Results:
Timely start of immunisation occurs in 60.5% of preterm infants in the Netherlands. The proportion of infants receiving the first immunisation on time was lowest for the group with GA <28 weeks (37%). The mean age of the first immunisation across all GA groups was 62.7 days (range 33-118) and differed significantly between GA group <28 weeks and the other two GA groups of 28-32 and 32-36 weeks (p < 0.001). Similar results were seen when stratified by BW. Multivariate analysis showed that low socioeconomic status (SES) and prolonged hospitalisation beyond 37 weeks each negatively influenced timeliness of the first immunisation.
Conclusion:
These findings indicate that start of immunisations was often delayed in prematures and differs for different GA groups, being lowest (37%) in infants <28 weeks GA. Lower SES and prolonged hospital stay beyond 37 weeks GA are important determinants of timeliness. Efforts to improve timeliness should focus most on counselling parents in lower SES.
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