Efficacy in pigs of a new inactivated vaccine combining porcine circovirus type 2 and Mycoplasma hyorhinis

Publication date: Available online 16 January 2020Source: Veterinary MicrobiologyAuthor(s): Yan-Wu Wei, Hong-Zhen Zhu, Li-Ping Huang, De-Li Xia, Hong-Li Wu, Hai-Qiao Bian, Li Feng, Chang-Ming LiuAbstractCoinfection with porcine circovirus type 2 (PCV2) and Mycoplasma hyorhinis (Mhr) can induce more-severe disease than a single infection with either. We evaluated the efficacy of a new vaccine combining inactivated PCV2 and Mhr, in a model of PCV2 and Mhr infection. Twenty-five 35-day-old PCV2- and Mhr-free pigs were randomly divided into five groups, with five pigs in each group. The pigs in groups 1 and 2 were vaccinated with the combined vaccine and then challenged with Mhr or PCV2, respectively. The pigs in groups 3 and 4 were not vaccinated and then challenged with PCV2 or Mhr, respectively, and group 5 was used as the unvaccinated unchallenged control. Two weeks after booster immunization via the intramuscular route, all the pigs except those in control group 5 were challenged with PCV2 or Mhr. All the pigs were euthanized 28 days after challenge. The pigs in vaccinated groups 1 and 2 showed a significant increase in weight after challenge with PCV2 or Mhr (P < 0.001), with an average daily gain (ADG) of 0.315 kg compared with unvaccinated groups 3 and 4 (0.279 kg). Mhr was isolated from the unvaccinated pig lungs after Mhr challenge, whereas it was not isolated from the vaccinated pigs. No PCV2 or Mhr was detected with PCR or histochemical staining in vaccinated ...
Source: Veterinary Microbiology - Category: Veterinary Research Source Type: research