VACCINE HANDLING
By Dr Mackie Hobson BSc(Agric),BVSc

Vaccines stimulate an animals’ immune system to produce a protective response against an organism. The immune system will then “remember” how to produce a response against the organism if challenged by the organism within a certain time frame. Vaccinating your goats cannot prevent exposure to infectious organisms, but they do increase an animals’ ability to fend off an infection or lessen the severity of the disease if it occurs.

Vaccines contain either killed or modified live viruses and/or bacteria. Both viruses and bacteria in these vaccines are made of protein complexes that have a very specific structure. If this structure is changed the effectiveness of the vaccine is greatly decreased. To be effective, killed vaccines require a large number of bacteria or viruses to be injected into the animal and modified live vaccines must have live viruses/bacteria to replicate once injected into the animal.  All of the structure of the vaccine must be intact for the vaccine to maintain its effectiveness.

Vaccination effectiveness is dependent on both animal factors and vaccine factors:

1:  Animal factors include age, condition, sickness, worm burden and stress.

2: Vaccine factors include vaccine temperature, exposure to sunlight, vaccine mixing in a clean syringe, contamination of the vaccine in the syringe or bottle, and the length of time the vaccine is mixed. 

Vaccine handling:

On Farm Critical Control Points for Vaccine Handling:

Transport and Storage:

• Always transport vaccines in an insulated container with sufficient frozen ice-packs to keep the desired temperature to point of destination. If the temperature of the vaccine is above refrigeration temperature or the vaccine is exposed to sunlight for too long the structure of the protein complexes is altered and the vaccine loses its effectiveness.
• On the farm keep vaccine in a reliable refrigerator with a min/max thermometer (4-8 C)
• Do not freeze vaccines.
• Have a contingency plan in case of fridge failure or extended power failure (Sufficient cooler box space and frozen ice-packs).

2. Taking the vaccines to the kraal to vaccinate:

• Transport vaccine to and keep in an insulated container with sufficient frozen ice-packs at the working area where animals are to be vaccinated.
• Keep vaccine out of direct sunlight.
• Administer reconstituted live vaccines within 1 hour. Live vaccines begin to loose potency as soon as they are mixed up.
• Do not attempt to preserve reconstituted vaccines in a fridge for future use. They will no longer be viable.
• Always consult the vaccine package insert for the correct information on storage, handling, dose, route of administration and possible precautions.
• Change needles regularly: Repeated syringe filling and needle puncture of the vaccine bottle may also carry contamination into the bottle.

Cleaning syringes:

(a): Syringes should be cleaned by washing with a detergent or soap (the outside only).

Detergents, soaps and disinfectants will kill modified live vaccines and/or alter the structure of the protein complexes in both killed and modified live vaccines. Cleaning a syringe with detergent and rinsing it a few times will leave enough detergent in the syringe to kill the virus or bacteria in a modified live vaccine and may change the structure of the protein complexes in a killed vaccine, making the vaccine ineffective.

(b): Disassemble the syringe, place in boiling water, the plunger lubricated with clean Vaseline and assemble them in a clean dust free area while they are still hot. They should be stored in a new zip-lock bag in the freezer.  Never get any detergent or disinfectants inside the syringe.

(c): Never use a syringe for a vaccine that has had an antibiotic in it.

(d): Never use a syringe for a modified live vaccine that has had a killed vaccine in it. All of these procedures will destroy the effectiveness of a vaccination program.

REFERENCE
Mel Pence DVM, MS, PAS, Diplomate ABVP (beef cattle)

University of Georgia, College of Veterinary Medicine