Common reasons for vaccination failure

 

  • Lack of maintenance of cold chain from the time of manufacture till vaccination.
  • Poor immune response in weak and improperly fed animals.
  • Lack of herd immunity due to only a few animals being vaccinated.
  • Poor quality of vaccine - Quality will deteriorate if repeatedly thawed and cooled.
  • Low  efficiency or ineffective vaccine – May occur in case of strain variation (eg.  FMD).