5 Reasons of Vaccination failure in Animals

Reasons of vaccination failure

(FMD Vaccine Failure taken as example)

A vaccine failure is when an animal develops a disease in spite of being vaccinated against it.

vaccine failure

1. Don't say: it's because of the quality of the vaccine,instead; Consider your quality of work too.

• Had you carried the vaccine below 4°c.
• Did you chill the needle before vaccination?
• Was the vial not in your pocket while you vaccinate?
• Did you vaccine all animals in herd including pregnant?
• Vaccine needs to stay in chilled condition 2° ~8°c.
• You keep it out and let it destabilize which adversely affects vaccine efficacy. 
• Friction of needle during vaccination is also significant. Increased temperature of needle makes a vaccine unstable.keeping vial in pocket also causes the same.
• if the vaccine separates into two phases on storage, if so is the case then the emulsion is not stable and is bound to fail.

2. If You observe swelling and pain in animal after vaccination, you can get rid of it by following steps:

a. Vaccinate in neck: Because more lymph nodes are present there to absorb vaccine.b. Shake vial well before vaccine is used.c. Never vaccinate sick and already under stress animals.d. Vaccinate early in the morning before 10 A.M.e. Avoid needles which are used many times and not sharp.f. advise message of muscles of skin where you are injecting vaccine.g. avoid vaccination on a rainy wet condition.h. Avoid vaccination on hot/harsh climatic conditions.i. Avoid vaccination in Immuno compromised animals.

3. If Vaccinated animal shows disease signs:

• Quite possible if booster dose of vaccine is not injected.
• Possible if vaccine is of poor quality.
• if u find an area prone to some disease against which you are vaccinating, you must vaccinate once every 3 months.

4. Why to vaccinate pregnant animals?

We need to vaccinate dams to get calves with ready made maternal antibodies for innate immunity in newborn calves because up to 3 months we don't vaccinate calves.Thus vaccinating dam protects the calf.

5. Never place vaccine vial directly on ice. It may cause crystal/frost formation in vaccine, denaturing its composition. Injecting such vaccine directly in body without thawing may cause shock especially in younger ones. 

Repeated vaccinations lower titer of antibodies produced in animal against a particular disease. So, Avoid overdosing of vaccines.