Contribution of Immunization Weeks toward improving coverage, access to services, and completion of recommended childhood vaccinations in Assam, India.

Recommended childhood vaccines have typically been provided through routine immunization programs. Recently, implementation of strategies that use campaign-like features for providing all the recommended childhood immunizations have been utilized to increase vaccination coverage. Between January 2006 and January 2008, Assam, India, conducted Immunization Weeks (IWs), a periodic campaign-like approach for providing the recommended childhood vaccines generally administered through the routine Universal Immunization Program (UIP). Using data from a household vaccination coverage survey conducted in 5 districts of Assam in late-2007/early-2008 among children 12-28 months of age, a secondary analysis was conducted for a subset of children with vaccination cards to assess the impacts of implementing the IW-strategy. Sixty-five percent of the 3310 surveyed children received at least one vaccine dose through an IW. Without IWs, coverage would likely have been lower for all vaccines (e.g., 75% measles vaccine coverage including IWs doses and an estimated 61% without IWs). The proportion of children receiving at least one IW dose was significantly different depending on the child's residence; 72% in hard-to-reach char areas, 66% in rural areas and 53% in urban areas (p=0.01). Overall, 2085 (63%) of children were fully vaccinated; of these 60% received a combination of IW and UIP doses, 35% received doses only through the UIP, and 5% received doses only through IWs. A delay in administration later than the recommended ages was found for both UIP doses and for IW doses (e.g., for measles vaccine, UIP doses were 6.9 weeks delayed and IW doses 13.6 weeks delayed). Among this sample of vaccinated children, IWs appeared to increase vaccination coverage and improve access to services in hard-to-reach areas. However, the UIP appeared to be a better system for ensuring that children received all doses in the recommended vaccination series.