Effect of introduction of pentavalent vaccine as replacement for Diphtheria-Tetanus-Pertussis and Hepatitis B vaccines on vaccination uptake in a health facility in Nigeria.

Abstract Background The introduction of a new vaccine into an immunization programme may affect the immunization system negatively or positively. The aim of this study is to determine the effect of the introduction of the pentavalent vaccine as replacement for DTP and Hepatitis B vaccines on timeliness, completion of the schedule and dropout rates among children attending a health facility. Methodology This was a retrospective cohort study which involved extracting immunization records of children attending the Institute of Child Health Child Welfare Clinic between June 2011 and May 2013. Pentavalent vaccine was introduced as a replacement for DTP and Hepatitis B vaccines in June 2012. The uptake, timeliness and dropout rates of different vaccines in the immunization schedule were determined for children who commenced immunization in the pre, peri and post introduction phases. Results A total of 1110 children were studied – 190, 410 and 510 who commenced vaccination in the pre, peri and post introduction phases of the pentavalent vaccine respectively. Uptake was significantly higher for all vaccines in the post introduction phase compared to pre and peri introduction phases ( p p p Conclusion The introduction of pentavalent vaccine significantly improved uptake of vaccines and completion of the schedule but resulted in prolonged delay in receipt of vaccines during the introduction period.