Review of the Oral Polio Vaccineimmunization Coverage with Regard to Polio Eradication in Zambia: 2000-2009

Abstract

Objectives: To review the Oral Polio Vaccine (OPV) immunization coverage (routine and supplemental) in Zambia from 2000 to 2009, with the view of identifying opportunities for system strengthening, given that routine immunization is the “bed rock” for polio eradication.

Design: A retrospective descriptive analysis design was conducted on secondary routine and supplemental immunization data for Zambia for the period 2000-2009, consisting of all children aged<5years who had received OPV country wide. Immunization performance was evaluated using the WHO-specified 90% target

Results: The target of 90% for Routine Immunization (RI)could not be reached in most provinces. Only Central province attained the target throughout the stated period. In 2004 and 2008, all provinces apart from Copperbelt attained the target. The 90%target for supplemental immunization activities were reached during all rounds of National Immunization Days (NIDs) apart from the first two (2) rounds in1996. The two rounds of Mopping –up immunization in 2002 attained the90% target

Conclusion: Routine immunization for the oral polio vaccine has been an integral part of immunization activities in Zambia. The WHO target for OPV immunization was not attained in most districts and provinces in the period under review. This situation needs to be addressed through partner collaboration to raise herd immunity in case of imported polio viruses. While RI alone cannot eradicate the disease, good routine OPV coverage reduces the incidence of polio and makes eradication feasible. It also prevents the re-establishment of poliovirus if it is re-introduced from other countries, through international travelers and migrant populations from conflict areas