Coverage rates and timeliness of nationally recommended vaccinations in Swiss preschool children: A descriptive analysis using claims data

Abstract

BACKGROUND
Low vaccination coverage as well as incomplete and delayed vaccinations pose a risk for the individual and population protection from vaccine-preventable diseases.

AIM
To describe vaccination patterns for nationally recommended basic and supplementary vaccinations in Swiss preschool children.

METHODS
We performed a descriptive study based on administrative claims data from a large Swiss health insurer (Helsana), in cohorts of children born between January 2010 and December 2016. We assessed coverage rates of nationally recommended basic vaccinations (i.e., diphtheria, tetanus, acellular pertussis [DTaP], Haemophilus influenzae type b [Hib], poliomyelitis [IPV], measles, mumps, and rubella [MMR]) and supplementary vaccinations (i.e., pneumococcal conjugate vaccine [PCV] and meningococcal group C conjugate vaccine [MCV]) for each birth cohort at the age of 13, 25, and 37 months. Additionally, we analysed timeliness of vaccinations using inverse Kaplan-Meier curves. Results were extrapolated to the Swiss population.

RESULTS
The study population comprised 563,216 children. We observed continuously increasing coverage rates for all vaccinations until the 2015 birth cohort. Overall, up-to-date status for the first dose of studied vaccinations at 37 months was as follows: DTaP: 95.4%; Hib: 94.9%; IPV: 95.5%; MMR: 86.8%; PCV: 83.2%; and MCV: 66.7%. On average, however, only seven out of ten children had an up-to-date status for completed basic vaccinations; even less (six out of ten) were up-to-date for recommended supplementary vaccinations at 37 months of age. Moreover, 4% of all analysed children received none of the recommended vaccinations and there were substantial regional differences. Delays in vaccine administration were common. The most frequently postponed basic vaccination was MMR; 22.6% of children vaccinated with the first dose experienced delays relative to age-appropriate standards.

CONCLUSION
To avoid future outbreaks and transmission of vaccine-preventable diseases, vaccination coverage in Switzerland must be further improved. In addition, more emphasis should be placed on timely vaccination.