Untimely vaccination – missed opportunities for protection against childhood infections at an early age

In most countries with vaccination problems, information on the timeliness and completeness of vaccination coverage of children is monitored only at certain age periods, namely at 12 or 24 months, which does not provide an idea of how timely, i.e. at the age determined by the National Immunization Schedule (NIS), young children were vaccinated against specific infections.

Objective. Determination of the impact of untimely vaccination on the schedule of subsequent vaccinations regulated by the NIS.

Materials and methods. The study was conducted in 2024 at a large Moscow pediatric outpatient clinic and included an analysis of electronic medical records, including form 063/u, of children registered with specialist doctors (n = 4783). In the cohort up to 6 years (inclusive) (n = 472), an analysis of vaccination against 7 infections (tuberculosis, hepatitis B, diphtheria, whooping cough, measles, rubella and mumps) was carried out and an assessment of the timeliness of the start and completion of the relevant vaccination complexes was carried out.

Results. In children with health problems, a significant delay in the timing of vaccinations in the age periods regulated by the NIS was found. A positive statistically significant correlation was found between the start of vaccinations according to the NIS and the age of subsequent vaccinations, which confirms that a delay in the first vaccinations has a complex effect on the entire system of protection against infections, and not just one of them.

Conclusion. Untimely vaccination determines the lack of protection against vaccine-preventable infections in children at the age periods most vulnerable to these infections. Monitoring the timeliness of the start of vaccination should become one of the indicators of the quality of the work of the district pediatric service.