Vaccine Pharmacovigilance: Adverse Effects Reported and the Pattern of Vaccines Utilization in a Tertiary Institution, Nigeria.

Abstract

Routine utilization of vaccines during immunization in children is a tool in the reduction of childhood morbidity and mortality of infectious disease globally. This requires pharmacovigilance to ensure safety among the category of patients. Due to the exposure of new born to vaccine at birth, it became necessary to assess the pattern of use and possible adverse reactions reported in a developing tertiary health institution, Nigeria. Archives of Children administered vaccines during routine immunization within a period of five years were assessed retrospectively by systematic random sampling. Three thousand five hundred and two cases were assessed by systematic randomization. Their ages were between one day and 9 months after delivery. Male/Female ratio 1:09. The pattern of complete immunization in children were Bacillus Calmette Guerin 3328(95.0%), Diphtheria, Pertusis, Tetanus 2588(73.9%), Hepatitis-B Vaccine 2814(80.4%),Yellow Fever Vaccine 2374(67.8%), Oral Polio Vaccine 2250(64.3%),Measles Vaccine 1982(56.6%). All were administered through their conventional routes. Crying and other reflexes were observed in all at the time of administration. Adverse effects reported were significantly dependent on the type of vaccine utilized P<0.0001 (Chisquare) Spearman rho=0.8. Commonly reported adverse effects were Pyrexia 7492(24.6%), Swollen site 12063(39.6%) and Restlessness 10931(35.9%). Paracetamol was the most common antipyretic utilized. Breast feeding was used in ameliorating crying and other reflexes. No death and anaphylactic reactions recorded during routine use. Routine pharmacovigilance is strongly recommended due to the commonly reported adverse effects in children at the centre. Adopting this principle will enhance reduction of childhood infection among children.

Key words: Pharmacovigilance, Vaccine, Children, Immunization.