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Timeliness of childhood vaccinations in Armenia, 2015-2016
Anya Agopian1, Heather Young1, Scott Quinlan1
1Department of Epidemiology, Milken Institute School of Public Health, George Washington University, 950 New Hampshire Ave NW 5(th) Floor, Washington, DC 20052, United States.
Insights
In Armenia, many children under three experience delayed vaccinations despite high overall coverage. Factors like female gender and lower maternal education are linked to these delays, impacting disease prevention.
Area of Science:
- Public Health
- Epidemiology
- Immunization Practices
Background:
- Vaccine-preventable disease control relies on timely vaccinations, not just high coverage.
- Previous studies in Armenia indicated delays in childhood immunizations.
- This study investigates vaccination timing and related factors in Armenian children.
Purpose of the Study:
- To analyze the timeliness of childhood vaccinations in Armenia.
- To identify factors associated with delayed vaccinations in children under three.
- To inform strategies for improving immunization schedule adherence.
Main Methods:
- Utilized data from the 2015-2016 Armenia Demographic and Health Survey (ADHS).
- Examined timing of BCG, DTP, Polio, and MCV vaccines using Kaplan-Meier and Cox proportional hazards models.
- Accounted for clustered sampling with a shared gamma frailty model.
Main Results:
- High vaccination coverage (80.6%-98.4%) but significant delays observed, especially in later vaccine doses.
- Over 50% of children had delayed third doses of DTP and Polio vaccines.
- Delayed vaccinations associated with female gender, region, prior delays, lower wealth, and maternal education.
Conclusions:
- A substantial proportion of Armenian children under three experience delayed vaccinations.
- Adherence to the immunization schedule is crucial for optimal protection against vaccine-preventable diseases.
- Targeted interventions may be needed to address identified factors contributing to vaccination delays.
Background:
Successful control of vaccine preventable diseases not only requires high coverage but also requires that vaccines are administered in a timely manner. Prior studies have examined the timing of vaccinations in Armenia and found that although vaccination coverage is high, children are not receiving the vaccinations in a timely manner. This study aims to further elucidate the timing and associated factors of childhood vaccinations among children in Armenia in 2015-2016.
Methods:
Data from the Armenia Demographic and Health Survey (ADHS) from 2015 to 2016 were used to examine the timing of WHO-recommended vaccinations during the first year of life of all living children under three years of age, which included a vaccine against tuberculosis (BCG), three doses of a diphtheria, pertussis and tetanus vaccine (DTP), three doses of a polio vaccine (Pol) and a measles-containing vaccine (MCV). The Kaplan-Meier method was used to assess age-appropriate receipt of vaccinations. Cox proportional hazards models with a shared gamma frailty to account for clustered sampling were used to determine factorsassociatedwith timely vaccinations.
Results:
Vaccination coverage was high ranging from 80.6% for the third dose of DTP to 98.4% for BCG, yet the proportion of children with delayed vaccinations increased with each dose in a series, with 51.9% and 48.5% having a delayed receipt of the third doses of DTP and Pol respectively. Factors associated with delayed vaccinations included female gender, certain regions of residence, previously delayed vaccinations, poorer wealth index and lower educational level of mother. There were no differences in timing of vaccinations between clusters.
Conclusions:
Although coverage was generally high, a high proportion of children under three in Armenia experienced delays in receiving the recommended vaccinations. Continued focus on adherence to the immunization schedule is necessary to ensure optimal coverage and protection for children in Armenia from vaccine preventable diseases.
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