Duration of Protective Immunity in Sheep Vaccinated with a Combined Vaccine against Peste des Petits Ruminants and Sheep Pox

In this study, the ability of the combined vaccine against peste des petits ruminants (PPR) (Nigeria strain 75/1) and sheep pox (SPP) (NISKhI strain) to form a protective immune response for 12 months in Kazakh breed fine-fleeced sheep aged 6–12 months was demonstrated. The duration of the protective immunity of immunized sheep from PPR and from SPP was evaluated using a serum neutralization test (SNT), followed by testing of the resistance of vaccinated sheep to infection with the field strain Kentau-7 of the PPRV and the virulent strain A of the SPPV. The PPR antibody response was additionally measured by c-ELISA. A single immunization of sheep with a combined vaccine in a volume of 2.0 mL, containing the PPR and SPP vaccine viruses in the titers of 103.0 TCID50/mL, provided reliable protection of animals from two infections simultaneously for 12 months (observation period). At the same time, in sheep immunized with the combined vaccine, antibodies of PPRV persisted for up to 12 months, with slight fluctuations. The combined vaccine induced 100% clinical protection against the field strain of PPRV and the virulent strain of SPPV in immunized sheep for up to 12 months, while unvaccinated animals became ill with the manifestation of clinical signs specific to PPRV and SPPV.

Terms of immunity formation in sheep vaccinated with a combined vaccine against peste des petits ruminants and sheeppox

The article presents the results of studies to determine the timing of the onset of immunity in sheep vaccinated with the associated vaccine against peste des petits ruminants (PPR) and sheep pox (SP). The timing of the onset of immunity in vaccinated animals against PPR and SP was evaluated by serum neutralization test (SNT) and by testing the withstood of vaccinated sheep to challenge infection with virulent strain "A" of SP virus. Protective tiers of virus neutralizing antibodies (VNA) to the PPRV virus were formed on 14 days with an average value of 2.8 log2 and reached up to 4.7 log2 on 21 days after vaccination, while immunity against the OO virus was formed on 7 days after vaccination with an average VNA titer of 1.8 log2, which increased to 4.3 log2 on 21 days after vaccination. All immunized sheep’s showed resistance to the virulent SP virus until the end of the experiment. Therefore, the experimental data obtained by us indicate a high degree of protection of animals immunized with the associated vaccine against PPR and SP, starting from day 7 from the SP virus and from day 14 from the PPR virus. Key words: combined vaccine, peste des petits ruminants, sheep pox, immunity.

KEMAMPUAN NETRALISASI KEKEBALAN TUBUH INDUK MELALUI KUNING TELUR AYAM PETELUR PADA VIRUS AI (H5N1) ISOLAT LAPANGAN

Day old chick in the first week of their life got the immunity from maternal antibody / immunoglobulin trough egg yolk. Hens with high antibody titer will decended the immunoglobulin to their harvest trough egg yolk. The research studied the capability of antibody anti H5N1 from egg yolk to neutralized H5N1 AIV. Twenty hens were devided to five group, one group as a control group were unvaccinated group and four other groups were vaccinated with H5N1 AI inactive vaccine produced by several Indonesia vaccine company. Four H5N1 AI inactive vaccines code VS1, VC1, VV1 and VM1 were vaccinated twice to group 2, 3, 4 and 5. A week after second vaccination the egg were collected and analyzed the antibody titer against H5N1 AIV by hemagglutination test using H5N1 AIV field isolates as standard virus (NG and LW)). The egg yolk were contain high antibody titer (above 26) collected and tested against H5N1 AIV field isolates NG and LW by serum neutralization test. The result showed that H5N1 AIV NG isolate were able to neutralized by antibody anti H5N1 AIV from egg yolk produced by hens vaccinated with VS1, VC1, VV1 and VM1, but LW isolate were able to neutralized by showed that H5N1 AIV NG isolate were able to neutralized by antibody anti H5N1 AIV from egg yolk produced by hens vaccinated with VS1, VC1, and VM1. It’s concluded that hens were vaccinated with H5N1 AI inactive vaccine were able to protect their off spring against H5N1 AIV from the field by transferred maternal antibody trough the egg yolk with titer above 26.

Development of a High-Throughput Serum Neutralization Test Using Recombinant Pestiviruses Possessing a Small Reporter Tag

A serum neutralization test (SNT) is an essential method for the serological diagnosis of pestivirus infections, including classical swine fever, because of the cross reactivity of antibodies against pestiviruses and the non-quantitative properties of antibodies in an enzyme-linked immunosorbent assay. In conventional SNTs, an immunoperoxidase assay or observation of cytopathic effect after incubation for 3 to 7 days is needed to determine the SNT titer, which requires labor-intensive or time-consuming procedures. Therefore, a new SNT, based on the luciferase system and using classical swine fever virus, bovine viral diarrhea virus, and border disease virus possessing the 11-amino-acid subunit derived from NanoLuc luciferase was developed and evaluated; this approach enabled the rapid and easy determination of the SNT titer using a luminometer. In the new method, SNT titers can be determined tentatively at 2 days post-infection (dpi) and are comparable to those obtained by conventional SNTs at 3 or 4 dpi. In conclusion, the luciferase-based SNT can replace conventional SNTs as a high-throughput antibody test for pestivirus infections.

Type-specific seroprevalence of bluetongue in India during 2018 and 2019

Background and Aim: Bluetongue (BT) is a major disease of sheep and goats and is endemic to India. It is known to cause significant economic losses to the sheep industry. The current study aimed to determine the type-specific seroprevalence of BT in sheep population of India during 2018-2019. Materials and Methods: Blood samples (n=405) were collected from 6 months to 1 year old sheep from six districts (Nalgonda, Karimnagar, Khammam, Mahabubnagar, Warangal, and Ranga Reddy) of Telangana state, India. Group- and type-specific seroprevalence (against BT virus [BTV] serotypes BTV-1, 2, 4, 5, 9, 10, 12, 16, 21, 23, and 24) was studied by competitive enzyme-linked immunosorbent assay and serum neutralization test, respectively. Results: Results showed an overall seroprevalence of 14.81% (n=60) with the highest seroprevalence of 50% in Khammam district. Seroprevalence of BTV-1, 2, 4, 5, 9, 10, 12, 16, 21, 23, and 24 was noted as 16.66%, 11.66%, 31.66%, 11.66%, 05%, 6.66%, 16.66%, 8.33%, 13.33%, 6.66%, and 16.66%, respectively. The majority of the sera neutralized more than 1 serotype, indicating superinfection or circulation of multiple serotypes in the sampled flocks. This mixed seroprevalence was observed in 43.33% of the sera with number of BTV serotype-specific antibodies ranging from two to eight in individual animals. Conclusion: Regular monitoring of circulating serotypes, especially in young herds, elucidates pattern of dominating serotypes in a particular area during a season. This knowledge can be applied to design appropriate vaccination strategies by including particular serotypes of virus as part of a multivalent vaccine for a particular period, in a particular area.

Bovine herpesvirus type 1 in cumulus-oocyte complexes collected from naturally infected cows

The objective of this work was to investigate the presence of bovine herpesvirus type 1 (BoHV-1) in follicular fluid and in cumulus-oocyte complexes (COC) recovered from naturally infected cows but with no clinical signs of the disease. Cows that were seropositive (n=38) or seronegative (n=8, control) to infectious bovine rhinotracheitis were selected after a serum neutralization test in microplates. The presence of the virus was investigated by PCR in COC and in follicular fluid. Viral DNA was not found in any of the samples. The obtained results suggest that serologically positive cows with no clinical signs of the disease offer negligible risk of transmitting BoHV-1 by COC or follicular fluid.

EFFECT OF VITAMIN-MINERAL PREMIX ON IMMUNE RESPONSE OF BABY CHICK RANIKHET DISEASE VACCINE IN CHICKS

A total of 150 (75 broiler and 75 layer) apparently healthy chicks were used to investigate the effect of vitamin-mineral premix on immune responses of Newcastle disease (ND) vaccine (Baby Chick Ranikhet Disease Vaccine, F-strain) during the period from January to March 2003. The chicks were divided into six groups namely group A, B and C for broiler and group D, E and F for layer birds consisting of 25 birds in each group. Chicks of group A, C, D and F were supplied with vitamin-mineral premix containing feed and chicks of group B and E were supplied with vitamin-mineral deficient feed. The chicks of group A, B, D and E were primarily vaccinated with 0. 1 ml of BCRDV of 1065 EID50/0. 1 ml per bird through intraocular route at the age of day 3 and were revaccinated with the same vaccine at the age of day 17. Birds of group C and F were kept as unvaccinated control. Chickens of all the groups were challenged with the virulent isolate of NDV @ 0.5 ml/bird IM (1045 EID50/0.1 ml) after two weeks of secondary vaccination. Titres were determined before and after vaccination by hemagglutination test (HI) test and serum neutralization test (SNT) was performed to measure the potency of immune serum. The HI titres of birds of groups A, B, D and E were 128, 16, 128 and 128 respectively after primary vaccination and 256, 128, 256 and 256 respectively after secondary vaccination. From the study it was found that among the experimental layer birds, no difference was noticed on the immune response to BCRDV. On the other hand, among the experimental broiler birds, birds of group A revealed higher HI titre compared to the birds of group B. Results of serum neutralization test indicated that the sera of birds possessing HI titre ?128 demonstrated a good level of virus neutralizing activity of ?7.60. The birds possessing HI titre of 128 ± 0.00 did not show any clinical signs of ND following challenge and the survivability was recorded as 100%. It may be concluded that supplementation of vitamin-mineral premix to the diet induces better immune response following vaccination with BCRDV in broiler chickens compared to the layer chickens.