When a new kitten or puppy is welcomed in to our homes and hearts we take all the precautions to ensure a happy and healthy little one.

From cute accessories, to the best food and recommended vaccinations, RESPONSIBLE owners ensure they do their best.

It is therefore so sad if regardless of best efforts their pets still get sick especially if they develop a disease which they are fully vaccinated against.

So why do vaccine failures happen?

There are three main categories of causes why vaccines fail to give protection

• Patient factors
• Vaccine factors
• Virus factors

Patient factors

When puppies receive their first vaccination shortly after weaning maternal antibodies ARE STILL in circulation which interferes with the vaccine. Research showed that the age at which puppies were able to respond to a vaccine and develop protection covered a wide period. At 9 weeks 40% of puppies in this study were able to respond to the vaccine,  the number increased to 60% at 16 weeks and 95% at 18 weeks. This shows the importance of repeating vaccination in young puppies.

The nutritional status and general health also contributes to the immune system’s ability to respond.

Certain breeds of dogs may be more susceptible to certain diseases. The black and tan coloured dogs appear to be MORE PRONE to developing parvo virus infection.

You may be interested in why the Parvovirus thrives in warmer months.

If a puppy is vaccinated while feverish the fever may inhibit the response of the immune system.

If the patient is immune suppressed at time of vaccination the response will also be inadequate.

Vaccine factors

The efficancy of the vaccine can be affected if it is not stored correctly or administered in the recommended way.

Viral factors

Different strains of viruses causes the same disease. If a mutation occurs, a new strain may develop which the vaccine will not protect against.

If the recommended interval between vaccines is not followed a break in protection may occur.

If you are concerned about your pet’s ability to respond to a vaccination discuss it with your vet.

Ensure that you follow the recommendation ACCURATELY.
A well fed, parasite free puppy has a better chance to respond to vaccines compared to the one which is challenged by concurrent disease or malnutrition.

By Dr Adel Ferreira