Research
Method
In accordance with the European Pharmacopeia monograph, seven 8- to 9-week-old, purebred, Specific Pathogen Free (SPF) beagle dogs were used. The study was designed as a controlled, randomized, laboratory study with two test groups of 2 or 5 male or female dogs. Group 1, which contained 2 dogs (1 male and 1 female dog) was vaccinated twice with the control article (sterile water) three weeks apart on day 0 and day 21. Group 2, containing 5 dogs (2 males and 3 females) was vaccinated subcutaneously with Vanguard® 7 (minimum release titer) three weeks apart on day 0 and day 21. Three weeks following the second vaccination, on day 42, both groups were challenged orally with the virulent German CPV2c field strain CPV-7/97 (105 TCID50 per dose). Blood samples were collected for serology by haemagglutination (HA) inhibition (HAI) tests 8 days prior to the first vaccination (day -8), on the day of the second vaccination (day 21), on the day of challenge (day 42) and at study completion (day 56). Day 42 samples were also analyzed by serum neutralization test for neutralizing antibodies to CPV-2c. Body weights were determined 8 days prior to the first vaccination (day -8), on the day of first vaccination (day 0) and at study completion (day 56). Clinical observations including rectal temperatures were recorded daily from the day of first vaccination (day 0) until the end of the study 14 days following challenge (day 56). Injection site evaluations were performed on all vaccinated animals from the day of first vaccination (day 0) until challenge (day 42). Redness was scored on a scale of 1 to 4; swelling on a scale of 1 to 5; heat on a scale of 1 to 3; and pain on a scale of 1 to 2. White Blood Cell (WBC) counts were performed 3 times pre-challenge, on days 38, 40 and 42, and multiple times post-challenge on days 45, 47, 49, 52 and 56. Individual fecal samples were collected daily from the day of challenge to the end of the study and analyzed by the HA test. All experimental procedures were conducted in compliance with the relevant German legislation and were ethically reviewed.
