(Ph. Eur. monograph 2525)
1 DEFINITION
Bordetella bronchiseptica Vaccine (live) for dogs is a preparation of a suitable strain of Bordetella bronchiseptica. This monograph applies to vaccines intended for the active immunisation of dogs against respiratory disease caused by B. bronchiseptica.
2 PRODUCTION
2-1 PREPARATION OF THE VACCINE
The vaccine strain is grown in a suitable medium.
2-2 CHOICE OF VACCINE COMPOSITION
The vaccine strain is shown to be satisfactory with respect to safety (5.2.6) and efficacy (5.2.7) for the dogs for which it is intended.
The following tests for safety (section 2-2-1), excretion and transmission of the vaccine strain (section 2-2-2), increase in virulence (section 2-2-3) and immunogenicity (section 2-2-4) may be used during the demonstration of safety and efficacy.
2-2-1 Safety
Carry out the test for each route and method of administration to be recommended for vaccination using in each case dogs not older than the minimum age to be recommended for vaccination. The vaccine strain to be administered is at the least attenuated passage level that will be present in a batch of the vaccine.
For each test, use not fewer than 8 dogs, shown to be free from B. bronchiseptica and that do not have antibodies against B. bronchiseptica. Administer to each dog a quantity of the vaccine strain equivalent to not less than 10 times the maximum number of live bacteria likely to be contained in 1 dose of the vaccine. Observe the dogs at least daily for at
least 14 days. The vaccine strain complies with the test if no dog shows abnormal local or systemic reactions or dies from causes attributable to the vaccine strain.
2-2-2 Excretion and transmission of the vaccine strain
Use dogs not older than 10 weeks of age. Administer the strain by the route to be recommended for vaccination most likely to lead to excretion. The vaccine strain to be administered is at the least attenuated passage level that will be present in a Bordetella Bronchiseptica Vaccine (live) for Dogs batch of the vaccine.
For each test, use not fewer than 8 dogs, shown to be free from B. bronchiseptica and that do not have antibodies against B. bronchiseptica. Administer to not fewer than 4 dogs a quantity of the vaccine strain equivalent to not less than the maximum number of live bacteria likely to be contained in 1 dose of the vaccine. 2 days after vaccination add 4 dogs to the group of vaccinated dogs. Observe the animals for 70 days. Collect nasal swabs or washings from each dog at weekly intervals. Verify the presence of the excreted vaccine strain with a suitable method.
The vaccine strain complies with the test if no dog shows abnormal local or systemic reactions or dies from causes attributable to the vaccine strain.
The results are noted and used to formulate the label statement (whether the vaccinated strain is excreted, the period over which there is excretion and whether or not the vaccine strain spreads to in-contact dogs).
2-2-3 Increase in virulence
Carry out the test according to general chapter 5.2.6 using dogs not older than 10 weeks of age, which are free from B. bronchiseptica and that do not have antibodies against B. bronchiseptica. If the properties of the vaccine strain allow sequential passage through 5 groups via natural spreading, this method may be used, otherwise passage as described below is carried out.
Administer to each dog by a route to be recommended a quantity of the vaccine strain that will allow recovery of bacteria for the passages described below. Administer the strain by the route to be recommended for vaccination most likely to lead to reversion to virulence. On one occasion between 4 and 6 days after administration, collect nasal swabs or washings from each dog, verify the presence of bacteria and pool positive samples. Administer 1 mL of the pooled samples by a suitable route (for example, the intranasal route) to each dog of the next group. Carry out this passage operation not fewer than 4 times; verify the presence of the bacteria at each passage. If the bacteria are not found at a passage level, repeat the passage by administration to a group of 10 animals.
If the 5th group of animals shows no evidence of an increase in virulence indicative of reversion during the observation period, further testing is not required. Otherwise, carry out an additional safety test and compare the clinical signs and any relevant parameters in a group of at least 8 animals receiving the material used for the 1st passage and another similar group receiving the bacteria at the final passage level.
The vaccine strain complies with the test if no indication of increased virulence of the bacteria recovered for the final passage compared with the material used for the 1st passage is observed. If bacteria are not recovered after an initial passage in 2 animals and a subsequent repeat passage in 10 animals, the vaccine strain also complies with the test.
2-2-4 Immunogenicity
A test is carried out for each route and method of administration to be recommended for vaccination using in each case dogs of the minimum age to be recommended. The quantity of vaccine strain to be administered to each dog is not greater than the minimum number of live bacteria to be stated on the label and the strain is at the most attenuated passage level that will be present in a batch of vaccine.
Use for the test not fewer than 15 dogs which are free from B. bronchiseptica and that do not have antibodies against B. bronchiseptica. Vaccinate not fewer than 10 dogs, according to the schedule to be recommended. Maintain not fewer than 5 dogs as controls. Challenge each dog after 20-22 days by the intranasal route with a quantity of a suspension of virulent B. bronchiseptica sufficient to cause typical signs of respiratory disease in a dog that does not have antibodies against B. bronchiseptica. Observe the dogs at least daily for 14 days after challenge. Collect nasal swabs or washings from each dog daily from day 2 to 14 after challenge and determine the number of excreted B. bronchiseptica in each sample. Use a scoring system to record the signs of respiratory disease in each dog.
The test is invalid if more than 20 per cent of the controls show no typical signs of the disease.
The vaccine complies with the test if there is a significant decrease in the score for respiratory signs and in the number of B. bronchiseptica excreted in vaccinates compared to controls.
3 BATCH TESTS
3-1 Identification
The vaccine strain is identified by suitable methods.
3-2 Bacteria and fungi
Carry out the test by inoculation of suitable media. The vaccine complies with the test if it does not contain extraneous micro-organisms. Any diluent supplied for reconstitution of the vaccine complies with the test for sterility prescribed in the monograph Vaccines for veterinary use (0062).
3-3 Live bacteria
Make a count of live bacteria on a solid medium suitable for the culture of B. bronchiseptica. The vaccine complies with the test if 1 dose contains not less than the minimum number of live B. bronchiseptica stated on the label.
3-4 Potency
The vaccine complies with the requirements of the test prescribed under Immunogenicity (section 2-2-4) when administered by a recommended route and method. It is not necessary to carry out the potency test for each batch of the vaccine if it has been carried out on a representative batch using a vaccinating dose containing not more than the minimum number of live B. bronchiseptica stated on the label.
4 LABELLING
The label states:
— where applicable, the period after vaccination during which the vaccine is excreted;
— where applicable, that the vaccine strain may be transmitted to other dogs.
