Missed opportunities and inappropriately given vaccines reduce immunisation coverage in facilities that serve slum areas of Nairobi.

OBJECTIVES To quantify missed opportunities for immunisation, document reasons for their occurrence and evaluate the extent of inappropriately given vaccine doses. DESIGN A cross sectional study of children under two years of age attending health facilities. SETTING Six health facilities predominantly serving the slums of Nairobi. METHODOLOGY Information on vaccination was extracted from child immunisation cards as well as from mothers or guardians of children. RESULTS Effective immunisation coverage for Bacille-Callmette Guerin (BCG) was 91%. Coverage for the birth dose, first, second, and third doses of oral polio vaccine (OPV0, OPVI, OPV2, and OPV3) was 44%, 83%, 79% and 75% respectively. Effective coverage for first, second and third doses of diphtheria-pertusis-tetanus (DPTI, DPT2 and DPT3) vaccine was 88%, 87% and 85% respectively. Measles coverage was 80%. Immunisation coverage for all antigens except OPV0 and OPV3 would have been increased to over 90% had missed immunisation opportunities and inappropriately administered vaccination been avoided. There would have been an 11% increase in OPV3 coverage to 86%. Increases in coverage for OPVI and OPV2 would have been 16% and 18% respectively. Coverage would have increased by 10% for diphtheria pertusistetanus (DPT) doses DPTI and DPT2, and 7% for DPT3. Measles immunisation coverage would have increased by 19% had missed immunisation opportunities and inappropriately administered vaccinations been avoided. The overall missed opportunities rate was 3%. The proportions of missed opportunities were higher for the OPV series than DPT series. CONCLUSION Missed immunisation opportunities among clinic attendees in Nairobi occur and routine supervision should be strengthened in these health facilities in order to minimise such missed opportunities and inappropriately administered vaccines.