Improved coverage and timing of childhood vaccinations in two post-Soviet countries, Armenia and Kyrgyzstan.

A Schweitzer,G Krause,M K Akmatov,F Pessler

doi:10.1186/s12889-015-2091-9

Abstract

BackgroundTiming of childhood vaccinations has received close attention in many countries. Little is known about the trends in correctly timed vaccination in former Soviet countries. We examined trends in vaccination coverage and correct timing of vaccination in two post-Soviet countries, Armenia and Kyrgyzstan, and analyzed factors associated with delayed vaccinations.MethodsWe used data from the Demographic and Health Surveys; the surveys were conducted in 2000 (n = 1726), 2005 (n = 1430) and 2010 (n = 1473) in Armenia and in 1997 (n = 1127) and 2012 (n = 4363) in Kyrgyzstan. We applied the Kaplan-Meier method to estimate age-specific vaccination coverage with diphtheria, tetanus and pertussis (DTP) vaccine and a measles-containing vaccine (MCV). A Cox proportional hazard regression with shared frailty was used to examine factors associated with delayed vaccinations.ResultsVaccination coverage for all three doses of the DTP vaccine increased in Armenia from 92 % in 2000 to 96 % in 2010. In Kyrgyzstan, DTP coverage was 96 % and 97 % in 1997 and 2012, respectively. Vaccination coverage for MCV increased from 89 % (Armenia, 2000) and 93 % (Kyrgyzstan, 1997) to 97 % (Armenia, 2010) and 98 % (Kyrgyzstan, 2012). The proportion of children with correctly timed vaccinations increased over time for all examined vaccinations in both countries. For example, the proportion of children in Armenia with correctly timed first DTP dose (DTP1) increased from 46 % (2000) to 66 % (2010). In Kyrgyzstan, the proportion of correctly timed DTP1 increased from 75 % (1997) to 87 % (2012). In Armenia, delays in the third DTP dose (DTP3) and MCV vaccinations were less likely to occur in the capital, whereas in Kyrgyzstan DTP3 and MCV start was delayed in the capital compared to other regions of the country. Also, in Armenia living in urban areas was associated with delayed vaccinations.ConclusionsVaccination coverage and timing of vaccination improved over the last years in both countries. Further efforts are needed to reduce regional differences in timely vaccinations.

Highlights

Timing of childhood vaccinations has received close attention in many countries
It is important to take the correct timing of vaccination into account, as relying exclusively on vaccination coverage alone can lead to a false assumption of disease protection [6, 10]
Characteristics of the samples In both countries, the proportion of the study population born in a health care facility and with higher maternal education level increased from 2000 to 2010 (Armenia) and from 1997 to 2012 (Kyrgyzstan), respectively (Table 2)

Summary

Introduction

Timing of childhood vaccinations has received close attention in many countries. Little is known about the trends in correctly timed vaccination in former Soviet countries. The timing of vaccination is increasingly recognized as another important target for optimal protection of children [1] and has received close attention. Timed (early or delayed) vaccination doses might explain the persistence or even the resurgence of vaccine-preventable infections, which is especially relevant for countries where high levels of vaccination coverage at milestone ages have been achieved [10, 11]. Outbreaks of diseases such as measles can occur in a population with high vaccination coverage [12]. It is important to take the correct timing of vaccination into account, as relying exclusively on vaccination coverage alone can lead to a false assumption of disease protection [6, 10]

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