engleski

Safety and immunomodulating effect of inactivated Parapox ovis virus given to newly hatched chickens by nebulisation

Objectives: Immunomodulating effect of new formulated inactivated Parapox ovis virus (IPOV) on immune response development after vaccination against Newcastle disease (ND) was investigated. Material and methods: Altogether 147 newly hatched chickens were disposed into four groups (A, B, C, and K). The first group, subdivided as A 1, A 2 and A 3, was exposed to the water suspension of IPOV for 30, 60 and 300 seconds respectively. Group B was exposed to the water suspension of commercial La Sota vaccine for 60 seconds and group C was submitted to the mixture of IPOV and La Sota vaccine suspension for 60 seconds. The control chickens weren't treated at all. All the medicine mentioned were applied by the ultrasonic nebulizer SONOVAC 095&reg ; ; ; ; ; which develops particles ranging 2 to 5 microns in diameter (Mazija and Stimac, 1995). To control the immune status blood samples were taken every 7 days starting on 1st day when blood was collected by heart puncture, and from 7th till 42nd day by wing vein puncture. Collected sera were analyzed by standard micro method of inhibition of hemaglutination to detect specific antibodies against vaccine virus. The scheme of the trial is shown on Table 1. Results: The IPOV didn't cause any clinically noticeable reaction in chickens, regardless the time of exposure to aerosol in SONOVAC 095&reg ; ; ; ; ; (groups A 1, A 2 and A 3). The mortality appeared in group B because of technical error in water supply (Table 2.). The body weight of chicken was not influenced by vaccination and where not significantly different between the experimental group (Figure 1.). Neither was maternal antibody level in chickens influenced by time of exposition to IPOV 30, 60 or 300 seconds (Table 3.). Active immunity to the given La Sota vaccine (Figure 2.) obviously was influenced by IPOV. Compared to the group B (LS 60'') and negative control chickens, those given vaccine and IPOV (group C) responded significantly higher. Wilcoxon matched pairs test revealed significant differences in HI titers starting from day 21 till the end of the trial (Table 4.). On 42nd day after vaccination it was still protective (1:23). Similar researches haven't been performed yet. Discussion: The IPOV products are known to stimulate immune responses to specific vaccines given parentheraly (Mayr, 1982.). Acting as immunomodulators they stimulate immune system and thus enhance resistance to opportunistic diseases. There are no available data on aerosol administration of such products by nebulisation. The method is known as highly efficacious in vaccination against ND (Mazija at al. 2001). It gives long life protection of broiler chickens after single vaccination of newly hatched chickens. Respiratory system compared to classic modes of vaccination, as a site of application gives much bigger surface for resorption of antigens (immunogens). Obviously the same has happened with combined IPOV and La Sota vaccine. The IPOV stimulates the efficacy of La Sota vaccine and therefore should be recommended for practical use.

safety; immunomodulation; inactivated Parapox ovis virus; chicken; nebulisation

nije evidentirano