However, immunization cannot compensate for poor biosecurity, unsanitary conditions, human error and etc. This is why birds under stress, in unsanitary conditions or not properly vaccinated may not be fully protected by vaccination programs. This is why it is important to focus on many areas of vaccination in regards to mixing, handling and ultimately delivery to the bird for the best protection and performance.

The first step to consider is proper mixing and handling of the vaccines. Store and prepare vaccines in a separate, clean and well ventilated room in the hatchery. The different forms and presentations of vaccines require different methods of preparation. Live cell associated Marek’s vaccines and vector vaccines are stored in liquid nitrogen. Proper PPE (personal protective equipment) needs to be worn when working with liquid nitrogen. Thaw the vaccine within 90 seconds in a 27°C water bath. Then transfer the vaccine into the diluent using an 18-G needle. A sterile blue dye may be mixed into the diluent before adding the vaccine. This protocol preserves the cell viability, and thus the vaccine titer. For killed vaccines, remove from the refrigerator 24 hours prior to use to allow the vaccine to warm to room temperature. For live respiratory vaccines, reconstitute live freeze-dried or frozen vaccines in fresh cool distilled water. Warm water can have a negative impact on the vaccine viability and cold water can chill the birds.

Another important area of focus is the equipment and operators. It is important to make sure all operators who are delivering the vaccine, individual or mass application, is properly trained to set-up, operate and maintain the equipment. The equipment must be checked prior and during vaccination to validate vaccine is being delivered through the needle or nozzle, correct dosage is being delivered, correct air pressure is set, position of the needle/nozzles is correct, etc. At the end of the vaccination period, it is also important to make sure the equipment is cleaned per the manufacturer’s recommendations. This is to not only help maintain the longevity and operation of the equipment, but also from a sanitary point of view. Quality control measures are a must.

Vaccination quality checks are also an important part of the vaccination process. Someone needs to be responsible on a daily basis to review and validate the vaccine is properly or improperly delivered to the birds. Corrective action plans need to be in place and followed. The methods used to validate the quality of vaccination will differ by vaccination technique. In addition, good hatchery management will also impact delivery of the vaccine. For example, a dehydrated bird will be harder to properly vaccinate.

A good vaccination program takes into consideration the bird’s immune system, the different types of vaccines available as well as the challenge in a production area. Furthermore, the program depends on good management practices as well as correct vaccine preparation and administration in the hatchery and on the farm. With these practices in place, vaccination can protect poultry effectively against many contagious and deadly diseases, as well as improve flock health, performance and ultimately efficiency of production.

Dr. Chris Fritts