Target species
Chickens (Broilers)
Indications for use
For active immunisation of broilers with maternally derived antibodies (MDA ELISA breakthrough titre of 115) to prevent clinical signs and to reduce loss of weight and bursal damage caused by Gumboro disease. The onset of immunity is 14 days and the duration 30 days post vaccination.
Contra-indications
Do not use in sick birds. Since no studies to demonstrate the safety of this vaccine when it is administered to layers and breeders have been carried out, its use is not recommended for these categories of the target species.
Special warnings for each target species
The optimal day of vaccination is calculated according to the Deventer's formula, using 115 as the ELISA breakthrough titre value.
Special precautions for use in animals
•The vaccine strain is excreted up to a maximum of 10 days; thus, during this time, it may spread to unvaccinated chickens.
•Appropriate veterinary and husbandry measures should be taken to avoid cross contamination of flocks.
•Do not use drinking water with chlorine or disinfectants.
•The vaccine should not be used in birds without maternally derived antibodies.
Special precautions to be taken by the person administering the veterinary medicinal product to animals
•Wash and disinfect hands and equipment after use.
•Personal protective equipment consisting of impervious gloves should be worn when handling the product.
•In the case of accidental ingestion, contact with the eyes, or spillage onto the skin seek medical advice immediately and show the package leaflet or the label to the physician.
Adverse reactions
In very rare cases a notable transient lymphocyte depletion can be observed in birds on day 7 post-vaccination. The repopulation of the follicles by lymphocytes starts after day 7 post-vaccination, being specially evident on 21 days post-vaccination. By day 28 post-vaccination only mild lesions remain in some birds. This does not result in an immune-supressive effect.
Use during pregnancy, lactation or lay
Do not use in layers and breeders.
Interactions
No information is available on the safety and efficacy of this product when used with any other veterinary medicinal product. A decision to use this vaccine before or after any other veterinary medicinal product therefore needs to be decided on a case by case basis.
Amounts to be administered and administration route
Administer one dose of the vaccine per chicken in drinking water.
Most of the commercial chicks are hatched with maternal antibodies which might neutralise the vaccine. Due to this fact it is required to calculate the proper vaccination time.
The optimum age for vaccination is calculated, after testing the level of maternal antibodies of 18-20 chicks of the flock, by means of the Deventer Formula.
According to this formula the optimum age of vaccination is as follows:
Optimum vaccination age =
{(Log2 IBD antibody ELISA titre of bird (%) - Log2 breakthrough titre of the vaccine) x t0.5}
+ age at sampling + correction 0-4
IBD antibody ELISA titre of bird (%):
ELISA titre of the bird (at sampling) representing a certain percentage of the flock that is desired to be susceptible to the vaccine at the time of the application
Breakthrough titre of the vaccine:
ELISA titre that the vaccine is able to breakthrough
t0.5:
Half-life time of the antibodies (ELISA titre) in the type of chickens being sampled
Age at sampling:
Age of the birds at sampling
Correction 0-4:
Extra days when the sampling was done at 0 to 4 days of age.
Reconstitution of the vaccine:
Open the vaccine vial and introduce 10ml of drinking water without chlorine or disinfectants. Shake gently until the complete reconstitution of the freeze-dried powder is achieved.
Other alternative is to open the vial under the water. The empty vial should be rinsed a couple of times to ensure the complete reconstitution of the vaccine.
Method of administration
It is important to use clean cold water, free from chlorine and other disinfectants.
The volume of water for reconstitution of the vaccine depends on the daily water consumption which is related to the age of the birds, the environment temperature and the management practices.
The volume of water should be adjusted to ensure that the vaccine solution is consumed in 1 hour up to 2 hours the maximum.
If the birds have higher or lower water requirements, adjust the volumes accordingly to ensure the proper water consumption time.
The following management practices should improve the vaccine intake:
- Water should be withheld for 1-2 hours prior vaccination to increase the thirst of the birds and ensure that all reconstituted vaccine is consumed within 1 to 2 hours.
- Bell drinker vaccination: It is recommended to empty and clean the bell drinkers during the water withholding period. When the water restriction period is finished the vaccine is reconstituted as indicated previously and it is delivered to the birds.
- Nipple drinker vaccination: A considerable amount of residual water might remain in the lines after the water withholding period. It is recommended to drain the lines and load them with the vaccine solution before allowing the birds to have access to the nipples.
- always ensure that the feed is available when vaccinating. The birds will not drink enough if they do not have access to feed.
Overdose
No effects other than those indicated above have been observed following administration of ten doses.
Withdrawal periods
Zero days.