This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Contraindications, AEFIs, Subject name: Social & Preventive Medicine
Most common cause of Vaccine failure is: 
Select and explain. 
A. Improper storage, B. Improper administration, C. Inappropriate manufacturing, D. Maternally derived antibodies
D: Maternally derived antibodies
Answer: D: Maternally derived antibodies 
Explanation: - 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.