Uses

For use in chickens, 18 day-old embryonated broiler hatching eggs.

For the active immunisation of chickens to prevent mortality, clinical disease and weight loss, and to reduce the acute lesions of bursa of Fabricius associated with infection with both classical and very virulent avian Infectious Bursal Disease (IBD) viruses.

The release of the vaccine virus from the complex (and therefore immunisation) is influenced by the natural decline of maternally derived antibodies (MDA), which has been found not to occur until MDA has reached relatively low levels. The onset of clinical protection is achieved within 1 day after the first signs of vaccine virus effect in the bursa of Fabricius. This is expected to occur between 3-4 weeks of age in broiler flocks hatching from eggs of layers immunised against IBD using the customary immunisation programs. Duration of immunity is at least 42 days.

The virulent challenge tests conducted to support the claim were carried out on broilers having an MDA ELISA titre of 6,000 (1 day old chick).

Field trials carried out showed that vaccine virus replication in the bursa of Fabricius occurs in broilers having at hatch MDA titre levels of up to 14,000 ELISA units, but the protection of these birds was evaluated only based on serological data and histology of the bursa of Fabricius.

Dosage and administration

The vaccine is to be administered once at the 18th day of embryonation using in-ovo equipment. The injection volume is 0.05 ml per dose. The vaccine is delivered to the amnion sac or, rarely, into the body of the embryo, causing no decrease in hatchability.

Reconstitution of the vaccine

1. Calculate and prepare the required volume of the reconstituted vaccine as follows

· a single vial containing 2000 doses of freeze dried component reconstitute in 100 ml solvent,

· a single vial containing 5000 doses of freeze dried component reconstitute in 250 ml solvent, or two vials, containing 2500 doses of freeze dried component reconstitute in 250 ml solvent.

· a single vial containing 10000 doses of freeze dried component reconstitute in 500 ml solvent, or two vials, containing 5000 doses of freeze dried component reconstitute in 500 ml solvent.

2. Draw up 2 ml of the solvent and transfer into the glass vial containing the lyophilised component.

3. Completely dissolve the vaccine by shaking gently and transfer it into the plastic solvent bottle.

4. Rinse the vial with another 2 ml liquid and transfer the rinsing liquid into the plastic solvent bottle.

5. Repeat this rinsing operation.

The reconstituted vaccine should be used within 2 hours.

Contra-indications, warnings, etc

Special warnings for each target species

The vaccine virus is excreted by vaccinated birds, can spread to susceptible birds and can be detected in unvaccinated birds 4-7 days later. In susceptible birds (i.e. without MDA) this may result in significant immunosupression and bursal damage.

The use of this vaccine is contraindicated in eggs coming from layer flocks not vaccinated according to an IBD immunisation program.

In-ovo injection equipment must be used for administration. The User’s Manual of the equipment must be followed strictly. Device(s) used for the reconstitution of the vaccine and for injection should be sterile and free from any residues of chemical disinfectant.

Before every in ovo application the vaccination technique has to be checked by use of a colour solution. The vaccine must be inoculated directly into the amniotic cavity or the embryo. A stab vaccinator may be used for in ovo vaccination. It must be guaranteed that the instrument administers the necessary vaccine dose into the amniotic cavity or the embryo reliably. Furthermore, the manufacturer's instructions have to be observed, especially with regard to needle length and air pressure. For cleaning of the instrument only products approved by the manufacturer may be used.

The vaccine contains a strain of "intermediate-plus" virulence.

In birds without MDA the inoculation of the vaccine results in significant immunosupression and bursal damage. Therefore, it is not recommended to vaccinate eggs coming from flocks with day-old MDA titre levels lower than 3,000 ELISA units.

Preliminary survey to be used to estimate MDA level of the chicks: 20, day-old chicks originating from the same breeding flock should be sampled to measure their serological status to IBDV. The results of this sampling will indicate if the MDA level can be expected to be at least 3000 ELISA units in the hatches of the following 4 weeks from this flock, and therefore that they are suitable for Cevac® Transmune vaccination. According to results and needs, this survey has to be repeated at different times of the laying period.

To control the spread of the virus, the immunisation devices used for injection and the hatchery premises should be decontaminated after vaccination.

Chickens from vaccinated eggs should not be mixed with chickens from unvaccinated eggs. Precautions should be taken regarding between-house spread. Whole site vaccination is recommended. Poultry houses should be decontaminated between batches of chickens.

Satisfactory protection can be achieved only in properly developed embryos at the 18th day of hatching. It is suggested to candle the eggs to be injected and to separate and discard dead embryos.

In vaccinated chickens, mild to moderate lymphocyte depletion is observed after the vaccine take, which is maximal at around 7 days after vaccine take. After 7 days, this depletion decreases and is followed by lymphocyte repopulation and regeneration of the bursa of Fabricius.

Special precautions to be taken by the person administering the medicinal product to animals

It is advised that vaccinating personnel wash and disinfect hands after use.

Use during pregnancy, lactation or lay

Do not use in eggs intended for hatching of layers or broiler breeders.

Interaction with other medicinal products and other forms of interaction

No information is available on the compatibility of this vaccine with any other. Therefore the safety and efficacy of this product when used with any other (either when used on the same day or at different times) has not been demonstrated.

Withdrawal period

Meat - Zero days

For animal treatment only. Keep out of reach and sight of children.

Pharmaceutical precautions

Store the freeze-dried product component between +2°C and +8°C. Protect from light.

Store the sterile liquid diluent below 25°C. Do not freeze.

Legal category

POM-V

Packaging Quantities

Freeze-dried component: 10 ml glass vial presented in a cardboard box of 20 vials containing 2000, 2500, 5000 or 10000 doses.

Sterile liquid diluent: plastic bottles of low density polyethylene presented in a cardboard box with 5 or 20 plastic bottles containing 100, 250 or 500 ml.

Not all pack sizes may be marketed.

Further information

Immunological properties

The product stimulates active immunity against very virulent infectious bursal disease viruses in broiler chickens from hens vaccinated against IBD. The vaccine contains the live intermediate plus IBDV strain Winterfield 2512 bound to specific immunoglobulins. Both components form a complex which is administered through vaccination.

The Winterfield 2512 vaccine virus, applied as a non-immune-complex vaccine results in a mean histological lesion score of 2.2 in the bursa of Fabricius, 28 days after vaccination (after oral vaccination of 1 day old SPF chicken with 10 doses). The severity and duration of lesions is less significant following administration of the immune-complex vaccine.