Errors which can lead to Adverse events following immunization



Too much vaccine given in one dose · Improper immunization site or route


Syringes and needles improperly sterilized


Vaccine reconstituted with incorrect diluents


Wrong amount of diluents used


Drug inadvertently substituted for vaccine or diluent


Vaccine prepared incorrectly for the use, e.g. an adsorbed vaccine not been shaken properly before use


Vaccine or diluent contaminated


Vaccine stored incorrectly


Vaccines are not standardized between manufacturers.


Contraindications ignored, e.g. a child who experienced a severe reaction after a previous dose of DTP is immunized with the same vaccine Inattention when reading labels on vials resulting in mistaken content.


Reconstituted vaccine not thrown out at the end of an immunization session and used at a subsequent one.