Vaccination protocols vary among breeders and owners and a lot of us just follow like sheep not actually understanding why we vaccinate, the efficacy of the vaccinations our vets use and the importance of boosters. Understanding the WHY will help us to make informed decisions about the health of our animals. Dr Mats Abatzidis, technical veterinarian, provides us with significant insight into the science of cat vaccinations.

All vaccines, whether they are developed for use in human or animal medicine, are designed with two major purposes in mind. The first purpose is to reduce the severity of the clinical signs should the person/animal contract the disease, and secondly, to increase the chances of survival by virtue of the less severe clinical signs.

The first point, is further supported by the fact that the most reliable way to test any vaccine, is to challenge the vaccinated animals with a far more potent strain of the virus/bacteria/parasite and measure the severity of the clinical studies as well as the survival rates. In addition, the latter also confirms that vaccines are not designed to prevent an animal/person from contracting a disease, but more importantly, designed to offer resistance to the patient should they get the disease. The main reason why vaccines do not prevent an animal from contracting the disease, is simply because there are a lot of factors beyond our control and the vaccines control in the environment that determine whether an animal will contract the disease or not.

Historically, annual vaccination had been recommended. There were two reasons. The most important was that the vaccine manufacturers at that time only had proof that the core vaccines provided immunity for one year. Later on, the vaccine manufacturers were able to complete longer duration studies as well as make some small changes to their products for some of them, which yielded results supportive of a three year duration of immunity.

The 3 year duration of immunity must be put into context

It only applies to certain diseases such as Rabies, Canine Distemper, Canine Parvovirus, Infectious Canine Hepatitis and Feline Panleukopaenia (not Canine Parainfluenza, Bordetella Bronchiseptica, Leptospirosis, Canine Herpes, Feline Rhinotracheitis, Feline Calicivirus, Feline Leukaemia, Feline Chlamydia).

What’s the big deal about cat vaccinations?

A HUGE percentage of dogs and cats in South Africa are considered either non-vaccinated or inappropriately vaccinated, creating a very high “infection pressure” on the smaller part of the population that is vaccinated. Leaving <10% of animals with some form of protection against the diseases we vaccinate for.

The latter is important because we cannot compare our country to other countries, as environmental conditions, challenges and vaccine intake by the population varies greatly. Should the challenge be greater than the protection acquired through inoculations, the animal will still contract the disease(s). For example, outbreak situation, immuno-suppression in individual animals, etc.

On the positive side, should a vaccinated animal contract the disease for which it was vaccinated and recover asymptomatically is not the same as preventing infection – but we will never know will we?

Vets recommend annual re-vaccination for active/travelling/working pets in South Africa because the risk of these diseases remains high (“high infection pressure”). On the converse, if you own a pet that never leaves your property or gets exposed to other animals (and neither do its companions) you may be able to justify a longer interval between booster vaccines. In addition to the latter, vaccination protocols were reassessed and the concept of “core” and “non-core vaccines” was introduced: “Core vaccines” are indicated in all animals, non-core ones only in individuals whose lifestyle, concurrent diseases or geographic situation places them at risk from specific diseases.

The second reason used to justify annual vaccination was that pets will benefit from an annual health check – usually given at the time of vaccination. An general physical examination facilitates the early detection of a number of very common conditions and diseases e.g. heart disease, kidney disease and tumours (cancer) and is an ideal opportunity to remind owners about parasite control (fleas, ticks, lice, worms, etc.), discuss management of skin disease, as well as neutering and the like.

The point we are making here, is that we should be more preventative in our approach to pet welfare and less reactive. We are currently waiting for things to go wrong before doing anything about it. We should be taking responsibility for our pets by budgeting for their basic needs and being preventative. Preventative medicine is always more affordable and less complicated. If we simply react to problems and the challenges posed by our environment, we will expose our pets to a lot of undue suffering, huge expenses and a lot of heart ache.


Following an enlightening Hill’s Breeder Seminar in October this year, and with years of experience behind us, we found a protocol that not only works for us but works for our cats and our decisions were validated by Dr Mats Abatzidis’ (B.Sc. Psys & Micro, B.V.Sc. UP of MSD Animal Health) lecture on the subject. Since we changed our protocol in 2015, we have been able to vaccinate kittens without worry of reaction or side effects. We cannot advise diverting from what we have recommended, because there is no way to know how your kitten will react to a different brand/strain of the vaccine.

“I have made a personal observation and I am posing a question. If I vaccinate a dog/cat with a vaccine containing strain A of a disease, and then give the very same animal its booster using a vaccine containing strain B (different strain) of the disease, will I still get the boostering effect on the first inoculation? The reason I pose the question, is because I was always taught that the recognition of pathogenic antigens is a very specific process, where each receptor will only have affinity to a very specific protein antigen upon which all immune cellular reactions are based on. If I change to strain B, will the stimulated receptors recognise the new antigen?

I am not convinced! The point I would like to make here, is that all vaccine manufacturers will tell you their trial results based on using the same antigens throughout the their vaccine protocol. I have never heard of or seen any literature (trials) where a variety of vaccine brands were used interchangeably within a vaccine protocol and the resultant immunity was measured and challenged. What occurs when we mix strains and avoid consistency is anybody’s guess. Thus, the only recommendation we can make at this point in time is to vaccinate using one chosen brand throughout the paediatric series of vaccines for dogs and cats and establishing as good as an immunity as possible in their first year of life.”


For this very reason above, we encourage owners to talk to their vets about our protocols and get informed about why we ask you stick to the brand, strain and frequency that we recommend.

Thank you to Hill’s and Dr Mats of MSD Animal Health for providing us with this enlightening article to help us educate our owners about Vaccinations and why they are important.