Recipe for vaccination success: 8 questions to ask!

The primary reason for vaccinating animals is to minimize the losses due to morbidity and mortality caused by all kind of pathogens. A vaccine helps to prevent a disease by boosting the animals’ immune system to produce antibodies that in turn fight the invading pathogen, protecting them against disease caused by this specific invader. Certain diseases are too widespread or difficult to eradicate and require a routine vaccination program.  

However, vaccination will never provide 100% protection against infectious diseases.  It is only one, but a very important, part of a complex preventive policy, of which biosecurity, hygiene and nutritional programs are equally essential components. 

Unfortunately, vaccination does not always mean efficient protection. A vaccination failure is defined as: “when the animals do not develop adequate antibody titre levels and/or are susceptible to a field disease outbreak, following vaccine administration”. In recent studies, we have seen seroconversion is only established in 23-45% of animals two weeks after vaccination (Van Hamme et al., 2019).   

There are a lot of factors determining vaccination efficiency. Often the vaccine is blamed, but a lot can go wrong in between vaccine development and preparation, and the production of protective antibodies by the animal, so other factors need to be considered. These 8 questions can help in finding the gap:  

1. Is the vaccination program adapted to the flock’s health situation? 

2. Did they administer and/or handle the vaccine correctly? 

3. Are there still maternal antibodies that could interfere with the vaccine strain present?

4. How is the general management of the farm? 

5. What is the sanitary status: are birds already infected before vaccination?

6. Is the vaccine quality/strain up to date?

7. What is the immune status of the animals? Are they too stressed, diseased, part of the vulnerable YOPI¹?

8. Did you consider any immune supporting ingredients supplementation through drinking water or feed?  

¹YOPI (young/old/pregnant/immunodeficient) group 

Managing those factors is not easy but it is feasible, first evaluate them thoroughly before you vaccinate! 

Optimizing vaccination efficacy in poultry

Vaccination programs are quite intensely used in poultry production, especially layers and breeders are undergoing massive standard vaccination programs. Vaccination programs in meat-type poultry are more concise, however, vaccination against specific pathogens is not uncommon.

Read here how to improve serological response to IBD vaccination in broilers.

Gilts are undergoing an intensive vaccination program, that may consist of vaccines against following diseases. Any tool to support the gilts during this vaccination program is welcome. In most regions gilts are vaccinated against following pathogens: PCV-2, Mycoplasma hyopneumoniae, Haemophilus parasuis, swine influenza, etc. Interested on how to optimize serological response to those vaccines, download our technical papers here.