3. CLINICAL INFORMATION
3.1 Target species
Chickens.
3.2 Indications for use for each target species
For active immunisation of chicken (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.
Onset of immunity: 14 days post vaccination.
Duration of immunity: 30 days post vaccination.
3.3 Contraindications
None.
3.4 Special warnings
Vaccinate healthy animals only.
The optimal day of vaccination is calculated according to the Deventer’s formula, applying an ELISA titre of 115 as the MDA breakthrough titre.
3.5 Special precautions for use
Special precautions for safe use in the target species:
Vaccinated chickens may excrete the vaccine strain up to 10 days following vaccination. During this time, the vaccine strain can spread to unvaccinated chicken.
Appropriate veterinary and husbandry measures should be taken to avoid spread of the vaccine strain to susceptible species.
The vaccine should not be used in birds without maternally derived antibodies (MDA).
Special precautions to be taken by the person administering the veterinary medicinal product to animals:
Personal protective equipment consisting of impervious gloves should be worn when handling the veterinary medicinal product.
Wash and disinfect hands and equipment after use.
In 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.
Special precautions for the protection of the environment:
Not applicable.
3.6 Adverse events
Chickens.
Very rare, (< 1 animal / 10 000 animals treated, including isolated reports): Bursa Fabricius lymphocyte depletion*
* a notable and 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 especially 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.
Reporting adverse events is important. It allows continuous safety monitoring of a veterinary medicinal product. Reports should be sent, preferably via a veterinarian, to either the marketing authorisation holder or its local representative or the national competent authority via the national reporting system. See the package leaflet for respective contact details.
3.7 Use during pregnancy, lactation or lay
Laying birds:
Do not use in birds in lay and breeding birds.
3.8 Interaction with other medicinal products and other forms of interaction
No information is available on the safety and efficacy of this vaccine 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 made on a case by case basis.
3.9 Administration routes and dosage
Administer one dose of the vaccine per chicken in the drinking water.
Most of the commercial chicks are hatched with maternal derived antibodies, which might neutralise the vaccine. Therefore, it is required to calculate the proper vaccination time. The optimum age for vaccination is calculated by the Deventer Formula, after testing the level of maternally derived antibodies of 18-20 chicks of the flock.
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 t 0.5:
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 and method of administration:
Only clean, cold, fresh, antiseptic and disinfectant free drinking water should be used for reconstitution of the vaccine.
Calculate the number of vials of vaccine required and the volume of water needed to vaccinate all the birds.
The needed 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 about 1 - 2 hours at the latest. If the birds have higher or lower water consumption times, adjust the volume accordingly to ensure the proper water consumption time.
Open the vaccine vial(s) and introduce 10 ml of water. Shake gently until the lyophilisate is completely dissolved. The reconstituted vaccine is a pinkish suspension. Transfer the suspension into a container containing the remaining volume for the final vaccine suspension. The empty vial(s) should be rinsed a couple of times to ensure the complete reconstitution of the vaccine.
Alternatively, fill a clean container with the appropriate amount of water, submerge each of the closed vaccine vials individually and open the vial(s) under water. Shake gently until the lyophilisate is completely dissolved. The empty vial should be rinsed a couple of times to ensure the complete reconstitution of the vaccine.
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.
3.10 Symptoms of overdose (and where applicable, emergency procedures and antidotes)
No effects other than those indicated in section 3.6 have been observed following administration of ten doses.
3.11 Special restrictions for use and special conditions for use, including restrictions on the use of antimicrobial and antiparasitic veterinary medicinal products in order to limit the risk of development of resistance
Not applicable.
3.12 Withdrawal periods
Zero days.