Common reasons for vaccination failure

 Common reasons for vaccination failure

1. Lack of maintenance of cold chain from the time of manufacture till vaccination.

2. Poor immune response in weak and improperly fed animals.

3. Lack of herd immunity due to only a few animals being vaccinated.

4. Poor quality of vaccine - Quality will deteriorate if repeatedly thawed and cooled.

5. Low  efficiency or ineffective vaccine – May occur in case of strain variation (eg.  FMD).