Adverse event following immunization in a Nigerian tertiary health institution

Abstract

Vaccine manufacturers develop products with the highest safety and effectiveness possible. But some very rare vaccine-related adverse events still occur. A descriptive retrospective study design was employed in this investigation. The investigation was limited to the four major health facilities in a metropolitan city that offer major immunization services to children. All cases of injection abscess or local reaction following vaccine administration from January 2004 to June 2006 were extracted from the records of each facility and included in the investigation. More than half of the cases reported were between 2 -4 months of age constituting 57.9% of all reported cases. The mean age of all reported cases was 4.368 ± 2.794 with a modal age of 2 months. Over half of all documented cases of adverse reactions following vaccine administration during the period under investigation were local swelling at site of injection (50.9%). About half of all cases documented (49.1%), were given DPT before development of adverse reactions. Almost all the cases of adverse reaction to vaccine administration (93%) were seen at the tertiary health facility. Cold chain equipment should be supplied and maintained at utmost working conditions at all health facilities to guarantee potency of vaccines.