Experiences from polio supplementary immunization activities in Anambra State, Nigeria

Routine immunization coverage is low in some States in Nigeria and contributes to the transmission of wild poliovirus. Anambra State has been polio-free since 2004. However, the risk of importation of poliovirus from travelers and migrants is a public health concern due to the commercial nature of the State. This paper reported experiences and lessons from supplementary immunization activities (SIAs) conducted in the State that will be useful to other settings experiencing low uptake of routine immunization.

The SIAs were conducted simultaneously in the 21 local government areas (LGAs) in Anambra State during January, March, and November 2010. Data were entered and analyzed in Excel spreadsheet and findings were summarized as frequencies and proportions.

A total of 1,187,866 children were vaccinated in January, 1,260,876 in March and 1,225,187 in November 2010. The State's cumulative coverage exceeded the target coverage of >90% in the three SIAs. All LGAs met the >90% target in January and March, but one LGA achieved 79% coverage in November. The proportion of zero-dose children decreased from 6% to 4.7%, and the vaccine wastage rate ranged from 6% to 6.6%. In that same year, the state did not achieve the target coverage of >80% for routine oral polio vaccine (OPV 3 ) immunization in any of the months and only 29% of the LGAs exceeded the routine OPV 3 target.

The State achieved high polio vaccination coverage through the SIAs, but coverage through routine immunization was low. Adopting proper planning and supervision, financial and political support, community involvement, improved vaccine logistics, and other measures utilized during the SIAs could help to improve routine immunization.