Most common cause of Vaccine failure is:
- Primary vaccination failure: Failure to serologically respond to vaccine: Too young age where Maternal antibodies interfere (MC Cause) Vaccine production problems Cold chain failure Inappropriate administration technique Immunodeficiency Poor health - Secondary vaccination failure: 'Waning immunity' where there is loss of vaccine induced protection in an individual who had previously seroconveed to vaccination. Causes are not well understood.
Improper storage
Improper administration
Inappropriate manufacturing
Maternally derived antibodies
Contraindications, AEFIs