What does it mean to say vaccines fail?
Vaccine failure is simply the inability of the vaccine to stimulate the required antibody or immunity in the chickens to resist a target disease. Vaccines are like guard or security operatives stationed at a location to arrest a threat before the threat becomes a societal problem. If the guard or security operatives are not equipped adequately to overcome the threat, there is a higher tendency that the threat would outwit the guard or security operatives, causing more havoc to the society, earlier than expected. This is a simple analogy of how vaccine fails.
The potency of vaccines can be strengthened or weakened by several factors. Aside from the potential of the vaccine itself, environmental conditions and handling of vaccines also greatly determine the success or failure of vaccine and vaccinations. In this vein, I thought it is worth sharing some of the possible reasons or causes of vaccine failure in chickens.
Time Of Vaccination
What time did you or are you supposed to administer vaccine during the day of vaccination?
I think this is a question every poultry keepers must always ask prior to vaccination. Administering vaccine is good to the health of the chickens, administering vaccines at the right day is better but administering vaccines at the right time of that day is best and most beneficial to the chickens. Time is life; time is a valuable asset that is equally distributed. As it applies to humans, so also does in chickens.
You cannot just carry out vaccination at any time you feel on the due date. Vaccines are best applied in the cooler part of the day, either early in the morning or late in the evening. Vaccines are more effective during this part of the day.
You may want to ask, why do I have to administer vaccine during the cooler part of the day?
The reason is that the birds are less prone to stress during this period. Vaccination is a stress-inducing operation on its own, not by the way the birds react but by the composition of the vaccine solution. This is why it is highly prohibited to stress the chickens, during and after vaccination, and encouraged to serve the chickens anti-stress prior and after vaccination.
If you administer the vaccine during other parts of the day, most likely the sunny part, the birds themselves would have been stressed, either as a result of feeding or flying around or the sun intensity, there is a high percentage of vaccine failure and outbreak of the prevented diseases earlier enough. Therefore, vaccination during the early part of the day has a high success rate.
Poor Dosage Of Vaccine
Vaccines come in dosage; they have been concentrated to serve a particular number of chickens. We have 1000 dose vaccine for 1000 birds, however, from experience, it is best you double-dose your birds to eliminate the doubt of failure. Truly, the vaccine costs more considering the price of purchase but lesser when compared to the risk of the failure of the single-dose vaccine. Do not be frugal in spending when it comes to poultry but spend wisely.
Inadequate Preparation For Vaccination
Many poultry farmers do not know they have to prepare their chickens for vaccination. Preparation of chicken for vaccination starts at about 2-3 days before vaccination and not the day of vaccination as most farmers practice.
Stop all forms of medication at least 3 days before vaccination; this eliminates the interference of the vaccine and the medications to increase the potency of the vaccine. Also, serve your birds multivitamins and anti-stress at about 3 days before vaccination and 3 days after vaccination; this helps alleviate stress and gives the chickens succor against the prangs of the vaccines faster.
Remember, vaccines induce stress; hence, you need to build an anti-stress within your birds for easy adaptability and resistance.
Wrong Usage Of Vaccines
It is not encouraging to know that some farmers do not know the purpose of vaccination and what vaccines are used for. Vaccination is only meant for healthy birds and not sick or weak birds; vaccines are not drugs, they do not treat diseases but prevent diseases. Do not waste your time, resources and your birds by vaccinating them when they are unhealthy, it would fail; treat them and ensure they are fine before vaccinating.
Poor Water Quality
The water you are diluting the vaccines in could be a potential inhibiting factor to the potency of the vaccines. Water contains many impurities, such as chlorine, heavy metals, acidity, and alkalinity, that can interfere with the reaction of the vaccine negatively, hence, it is best you check the quality of the water you are using or better still, use skimmed milk as a prophylactic measure to correct the water quality. Add 2.5 grams of skimmed milk per liter of the drinking water to eliminate the impurities in the water.
Poor Intake Of Vaccine Solution
At times, the failure of the vaccination may be as a result of poor intake of the vaccine solution by the birds. A vaccine is not palatable and does not have a good taste; on a good condition, your birds would not want to take it. You need to find a way to stimulate the birds to drink the vaccines if you do not want it to fail and waste. You need to stimulate thirst by withdrawing water from the birds about one hour before vaccination. For chicks in brooding pen, increase the brooder temperature, this makes the birds thirsty and willing to drink any liquid that comes their way.
Poor Handling Of Vaccine
The way you handle the vaccine prior to administering it could make it fail. Any activity you want to do with the vaccines and the vaccination operation should not be more than 1 hour; 30 – 45 minutes is ideal. The longer the vaccination process the higher the risk of its failure.
Be sure you dilute the vaccines in water you know the birds would finish under 45 minutes; discard any vaccine solution leftover or excess after one hour. Avoid direct exposure of vaccine to sunlight and avoid freezing vaccines. Do not cut-short or minimize the quantity of vaccine for any reason, a reduced vaccine may fail to induce the required immune response in your birds.
Stress Makes Vaccine Fails
I would not end this write up without emphasizing this. Stress is a huge factor that can make or mar your poultry farm. Stress is one of the major causes that make vaccines fail after administration. Stress could be of any form, heat stress majorly; it is highly recommended you serve your birds anti-stress or multivitamins prior to and after vaccination; it makes your birds recuperate quickly and aid the potency of the vaccine.
Lastly, adhere strictly to the instruction laid down by the manufacturer of the vaccine. when chickens are vaccinated without strict adherence to the recommended rate or in a poor environmental condition, there is a high tendency of vaccine failure and outbreak of the prevented diseases earlier than expected. However, when vaccines are applied at the recommended rate in good environmental conditions, the success rate and efficiency of the vaccination is often very high.
Therefore, vaccination should be taken very seriously to avoid failure.