Side effects and problems with pig vaccinations

Vaccination programs don't always go completely according to plan. Certain side effects and problems can arise when immunising the herd.

Common side effects

The main side effects of vaccinations include:

• local reaction or irritation at the injection site
• infection from an improperly administered or poor hygiene injection
• weight loss (or restricted weight gain in piglets)
• minor signs of the disease being vaccinated against.

The side effects depends on the type of vaccine being given. Live vaccine may lead to the development of disease symptoms whereas other types will not. Most pig vaccines are of the inactive (killed) type.

Mild signs of disease following vaccination can cause that disease to be transmitted to other animals, particularly those that have not received a vaccination, so it is wise to quarantine any animals with symptoms.

A vaccine does not guarantee a pig will remain disease-free. The vaccine may have been contaminated, or stored improperly or unhygienically. The animal may already have been carrying the disease at the time of vaccination. Also, vaccines against respiratory and intestinal disease are generally not as effective as those against other diseases.

Even after administering vaccines, it is vital to remain vigilant and look out for symptoms of illness in the herd.

Seek help from a veterinarian if anything unexpected or concerning is noticed.

Hygiene during vaccination

If using a bottled vaccine, use a sterilised needle to withdraw the vaccine into the syringe and use another needle to inject the pig.

Syringes or vaccinators must be clean and maintained to ensure good hygiene. Clean off any organic matter or dirt with warm soapy water and rinse thoroughly.

Sterilise by either boiling for 15 minutes or immersing in an approved disinfectant, then rinse with sterile water. If using a live attenuated vaccine, do not use a disinfectant unless the rinsing with sterile water effectively removes all of the disinfectant; sterilising by boiling is preferable.