There are multiple things we look for in a vaccine, but are we missing something when we look at just the price?

There are other elements that need to be looked at, for example the ease and versatility of the vaccine (timing, production stages and management), as well as the safety and efficacy of the vaccine (duration of immunity, contraindications and risks). How do these come together for the farmer, but more importantly, what is the benefit for the animal and herd?

What and why?

A perfect example is that of the reproduction and respiratory vaccines. What is better and why? Well, many can argue benefits for either type of vaccine [Modified live (MLV) and killed/attenuated], but what is important is choosing the one that suits your farming system. You need to ask yourself and your vet what is best for your farming system, because the vaccines available on the market are very different and thus need to be evaluated to ensure that the best immunity is generated. The most important factor is the difference of individual immunity and herd immunity.

to read more about the benefits and versatility of Hiprabovis 4.

om meer te lees oor die voordele en veeldoeligheid van Hiprabovis 4.

A case in point

A simple aspect could be the number of animals on a dairy farm: 12,5% younger than six months, 37,5% between six and 24 months, 20% adult stock open and 30% lactating and dry (pregnant) animals. This generates the following scenarios for herd immunity:

Modified live BVD/IBR vaccine: These types of vaccines should preferably be administered in animals over the age of six months and in the open periods prior to breeding (product registrations). The fact that some MLV products only have effective immunity that lasts up to eight months, could mean that the herd is not as protected as you would like. The current farming systems which can have animals experiencing delayed conceptions or odd oestrus patterns, means that there are prolonged periods between vaccinations (12-month interval). These delays can result in an estimated amount of around 40% of the herd having sufficient protective levels of immunity. This explains the reason for continued circulation of viruses in the herd, even though the farmer has been vaccinating his animals for many years.

Killed BVD/IBR vaccine: These types of vaccines can be used at any age and production stage due to its safety aspects (no abortions due to vaccine and no reverting back to an infectious strain). This means that the 12-month interval can be maintained for the herd and the target of maintaining over 60% of the herd being at a protective level of immunity, will be achieved. This is needed to reduce the circulation of viruses. Thus herd immunity protects those few that are not as effective at developing their individual immunity.

This is then complemented by the fact that killed vaccines have higher antigenic masses, meaning that the annual booster with a killed vaccine is stronger. An article by Prof Chris Chase from the Department of Veterinary and Biomedical Sciences, South Dakota State University, explains this important principal. Click here to read the article.

In conclusion

The take-home message here is that you need to understand why you are using a certain type of vaccine. For example, killed vaccines because of their safety (safe for pregnant animals), versatility (any age and any production stage), robustness of immunity (herd immunity through mass vaccination) and the foetal protection (reduction of abortions and prevention of PI calves). Be sure to actually look into the real return on investment when considering the ‘price’ of a vaccine. – Dr Grant van Lelyveld, TMM Ruminants, HIPRA Southern Africa