Susceptible female breeding sheep.
Indications for use
For the active immunisation of susceptible female breeding sheep to reduce abortion caused by Chlamydophila abortus infection. Challenge studies have demonstrated that protection against Enzootic abortion and excretion of Chlamydophila abortus post-challenge is undiminished for at least three years post vaccination with Enzovax. Field studies in endemically infected flocks maintaining a policy of vaccinating incoming ewes with Enzovax indicate that enzootic abortion levels remain very low in ewes vaccinated 4 years previously.
Do not vaccinate pregnant animals. Do not vaccinate animals less than 4 weeks before mating. Do not vaccinate animals which are being treated with antibiotics, particularly tetracyclines.
Special warnings for each target species
Chlamydophila abortus is only one of the causes of abortion in sheep. If the abortion rate remains unchanged in flocks which have been vaccinated with Enzovax it is recommended that veterinary advice is sought. The epidemiology of abortion due to Chlamydophila abortus in ewes involves a long incubation period. Ewes that abort in any lambing season have usually been infected at the previous lambing. Field trial data indicate that vaccinating incubating ewes will reduce the incidence of abortion, but a proportion can still go on to abort. Care should be taken in handling such abortions as susceptible humans may be at risk of infection. A good immune response is reliant on the reaction of an immunogenic agent and a fully competent immune system. Immunogenicity of the vaccine antigen will be reduced by poor storage or inappropriate administration. Immunocompetence of the animal may be compromised by a variety of factors including poor health, nutritional status, genetic factors, concurrent drug therapy and stress.
Special precautions for use
Enzovax should not be handled by pregnant women or women of child bearing age as the vaccine may cause abortion. Enzovax should not be handled by persons who are immuno-deficient (e.g. AIDS sufferers, persons undergoing chemotherapy or taking immuno-suppressive drugs). If in any doubt, you should consult your GP.
To the user:
Operators should wear gloves when handling the vaccine. Care should be taken to avoid self-injection, but if this occurs, immediate medical advice should be sought and the doctor informed that self-injection with a living chlamydophila vaccine has occurred.
To the physician:
Tetracycline therapy is the current recognised treatment for infection with Chlamydophila abortus in humans.
A transient temperature rise may be observed after vaccination (average of up to 1.5°C for a maximum of 3 days). In very rare cases abortions may occur where the vaccine strain can be identified.
Use during pregnancy, lactation or lay
Do not use during pregnancy.
Safety/and or efficacy data are available which demonstrate that this vaccine can be administered the same day but not mixed with Toxovax. However, it should be given at separate sites. No information is available on the safety and efficacy of this vaccine when used with any other veterinary medicinal product except the product mentioned above. 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.
Amounts to be administered and administration route
Dose: 2 ml by intramuscular or subcutaneous injection.
Reconstitution: The vaccine is reconstituted with Unisolve immediately prior to use, allowing 2 ml of solvent per dose. If using the vented transfer device push one end of the device through the centre of the vaccine vial using a firm, twisting action. Similarly, push the Unisolve vial onto the opposite end of the device taking care to ensure the spike penetrates the centre of the vial bung. Carefully allow solvent to flow into the vaccine vial without completely filling it. Ensure the vaccine plug is fully dissolved and then invert until all the vaccine suspension drains into the solvent vial. Remove the empty vaccine vial and the transfer spike from the solvent vial and place them into an appropriate disinfectant solution. Alternatively, remove approximately 5 ml of Unisolve from the vial with a syringe and needle, inject into the vaccine vial and swirl gently until the vaccine plug is fully dissolved. Remove the vaccine suspension from the vial, re-inject into the solvent vial and mix gently. Great care should be taken not to generate an aerosol. After reconstitution the vaccine should be kept cool and used as soon as possible (within 2 hours).
Administration: Ewe lambs, where it is intended to breed from them, may be vaccinated from 5 months of age. Shearlings and older ewes should be vaccinated during the 4 month period prior to mating. Vaccination must take place at least 4 weeks before mating.
Injection equipment: To minimise the risk of self-injection the vaccine should be administered using a disposable automatic syringe fitted with a guarded needle system according to the manufacturer's instructions. It is vital that a vented draw off tube is used with this equipment. Regular checks should be made to ensure the syringes are properly calibrated. Carefully attach the vial of reconstituted vaccine to the injection equipment and avoid creating aerosols during the priming process. It may be advisable to wear a visor while carrying out this operation.
Re-vaccination policy: Challenge studies have demonstrated that protection against Enzootic abortion and excretion of Chlamydophila abortus post-challenge is undiminished for at least three years post vaccination with Enzovax. Re-vaccination is recommended every 3-4 years depending on farm management practices and conditions.
Field studies in endemically infected flocks maintaining a policy of vaccinating incoming ewes with Enzovax indicate that enzootic abortion levels remain very low in ewes vaccinated 4 years previously.
No particular symptoms at ten times dose other than a transient pyrexic response similar to that seen after a single dose but up to 2 °C.
Meat and offal: 7 days.