Tuesday, March 18, 2008

Factors associated with non-completion of the vaccination series, Assam, India

Tove Ryman, Karen A. Wilkins, and Vance J. Dietz. Global Immunization Division, NCIRD, Centers for Disease Control and Prevention, 1600 Clifton Rd MS-E05, Atlanta, GA, USA

Learning Objectives for this Presentation:
By the end of the presentation participants will be able to:
1. Identify factors for non-completion of the vaccination series in Assam, India

Routine immunization (RI) coverage has been consistently low in Assam, a state in northeast India. A RI intervention and evaluation project is being conducted in two Assam districts with the goal of improving coverage.

To determine immunization coverage and factors associated with non-completion of the vaccination series.

A pre-intervention baseline survey was conducted in five (two intervention and three control) districts. Multi-stage sampling was used, with primary sampling units chosen proportional to estimated population size and divided into segments. Data on immunization status and household characteristics were collected from all children in the selected segments, who were aged 12 and 23 months in October 2005 (n=3587). Immunization coverage was based on immunization card and parental recall. Data were analyzed in SUDAAN.

Twenty-eight percent of children were fully vaccinated with the recommended vaccines by 12 months of age. Access to services, measured by receipt of DPT1, was 62% and the percent of children starting the DPT series, but not completing (dropout) was 34%. Factors significantly associated (p <0.05) with non-completion of vaccine series included having an illiterate mother (odds ratio [OR]: 2.2), belonging to the Muslim religion (OR: 2.0), and immunization sessions being offered less frequently than weekly (OR: 1.6).

Two-thirds of children in five districts in Assam are inadequately vaccinated by 12 months of age; a third of children who start vaccination do not complete the series. Efforts to improve coverage and reduce dropout should focus on increasing the frequency of sessions and identifying and overcoming barriers to immunization among Muslim populations and among less educated women. A post-intervention coverage survey is scheduled for early-2008.