animal; Africa; vaccines; diseases; vaccinate

Livestock production: How vaccines work against diseases

Question: Most insect-transmitted diseases, such as lumpy skin disease, are only seen during late summer and autumn. Why do I need to vaccinate against these diseases in spring?

First of all, farmers should understand how a vaccine works. Unlike antibiotics that kill bacteria, a vaccine prevents diseases caused by either bacteria or viruses.

In most cases, disease caused by viruses can only be avoided by using a vaccine, because the various antibiotics are not effective against viruses.

  • A vaccine is made from the same germs that cause disease in animals.
  • The germs in the vaccine are killed or changed in such a way that they will not make the animal sick.
  • After the vaccine is injected, the animal’s defence system is activated.
  • The body will now form white blood cells and antibodies to fight the bacteria or viruses in the vaccine.
  • Because the germs in the vaccine don’t cause damage to an animal’s body, it will develop a defence system (immunity) to fight the specific germ without affecting how its body works.
  • It takes time for an animal to build up immunity to the disease it was vaccinated against.
  • Some vaccines cannot be used for pregnant animals; they will have to be vaccinated after calving or lambing in the spring.

The following are important viral vaccines that must be used during spring:
Cattle: Lumpy skin disease and Rift Valley fever
Sheep: Blue tongue and Rift Valley fever

Also read:
Livestock production: Check and revise vaccination schedules

  • This article was written by Dr. Danie Odendaal and first appeared in Farming SA.

share this