Tuberculosis vaccination sequence effect on protection in wild boar

The Eurasian wild boar (Sus scrofa) is a reservoir for tuberculosis (TB) in which vaccination is a valuable tool for control. We evaluated the protection and immune response achieved by homologous and heterologous regimes administering BCG and heat-inactivated Mycobacterium bovis (IV). Twenty-one wild boar piglets were randomly allocated in five groups: Control, homologous BCG, homologous IV, heterologous IV-BCG, heterologous BCG-IV. Significant 67% and 66% total lesion score reductions were detected in homologous IV (IVx2) and heterologous IV-BCG groups when compared with Control group (F_4,16 = 6.393, p = 0.003; Bonferroni _{Control vs IVx2} p = 0.026, Tukey _{Control vs IV-BCG} p = 0.021). No significant differences were found for homologous BCG (although a 48% reduction in total lesion score was recorded) and BCG-IV (3% reduction). Heterologous regimes did not improve protection over homologous regimes in the wild boar model and showed variable results from no protection to similar protection as homologous regimes. Therefore, homologous regimes remain the best option to vaccinate wild boar against TB. Moreover, vaccine sequence dramatically influenced the outcome underlining the relevance of studying the effects of prior sensitization in the outcome of vaccination.     

Kinetics of NDV specific antibodies in chickens—V. Analysis of frequency distributions of antibody titers against Newcastle disease virus by investigation of random samples in chicken flocks

Chicks and chickens maintained under commercial conditions were vaccinated against Newcastle Disease via drinking water. Prior and after different times of vaccination blood samples were drawn from different numbers of birds and checked for HI antibodies. The modes of distribution of the antibody titers within the random sample were assayed. The following results were obtained:

1. 1. On the basis of the distribution of the serum titers can be concluded whether the antibody level within a flock is increasing or decreasing.

◦ —A right steep asymmetry can be observed up to 20 days post vaccination.

◦ —In the phase of maximal antibody levels an almost symmetric distribution of the titers is present.

◦ —In later times (more than three weeks p. vacc.) the distribution shows a left steep asymmetry (Poisson distribution).

2. 2. A poisson distribution is also observable during the elimination of maternal antibodies of chicks until complete elimination.

3. 3. The mode of distribution of the HI titers in sera of day-old chicks correlates with the mode of distribution of the dams. Therefore, conclusions are possible from the status of the chicks to the dams and reverse.

4. 4. Factors which interfere with the mode of distribution are:

◦ —Two or more peaks after vaccination of chickens. This indicates an uneven immune response within the flock.

◦ —Distributions with several peaks may also occur if flocks are composed of day-old chicks from parent flocks with different levels of antibody titers.

狂犬病毒中和抗体检测试验中病毒回归试验的重要性

狂犬病毒中和试验的病毒回归试验表明,病毒攻毒液的实际剂量与理论剂量不完全一致.建议在新版<中华人民共和国兽用生物制品质量标准>中增加对病毒攻毒实际剂量范围的规定,以使结果的判定更为合理.     

狂犬病病毒HEP-Flury M基因重排后在小鼠神经母细胞瘤细胞中的表型分析

【目的】探究狂犬病病毒HEP-Flury M基因重排对基因转录和蛋白表达的影响,揭示病毒在小鼠神经母细胞瘤(NA)细胞中的表型变化与M基因重排的相关性。【方法】通过荧光定量PCR、Western blot以及病毒在NA细胞中的生长和扩散试验,对亲本毒株rHEP-Flury和M基因重排毒株M2、M4在NA细胞中的基因转录、表达、生长和扩散进行比较。【结果】狂犬病病毒结构基因的转录和表达主要受病毒基因组RNA合成的影响,但是在一个完整转录过程中单个结构基因的转录比例与其所在位置相关,M基因重排病毒的Leader RNA (LeRNA)和L mRNA的转录比例显著高于亲本毒株rHEP-Flury。M基因重排病毒在NA细胞中的生长和扩散都劣于亲本毒株rHEPFlury。【结论】狂犬病病毒亲本毒株rHEP-Flury具有狂犬病病毒原始的基因组顺序,在NA细胞中的生长和扩散都明显优于M基因重排病毒。结构基因在基因组中的位置主要决定其在一次转录过程中的转录比例,进而影响病毒在NA细胞中的生长和扩散。     

上海市犬只狂犬病认定免疫点主要管理做法分析

强化犬只狂犬病免疫工作是从源头控制狂犬病的最有效措施。近年来,上海市按照《上海市养犬管理条例》的要求,通过严把免疫资质准入、规范内部管理、落实疫情报告责任、推进免疫质量考核等举措,使犬只狂犬病认定免疫点的布局日趋合理,文明服务更加规范,这已成为上海市民犬只狂犬病免疫的主渠道,免疫数量和质量逐年提升,构筑了良好的免疫屏障。今后在犬只狂犬病认定免疫点管理方面,上海市应强化疫苗源头管理,加大非法免疫惩处力度,合理认定免疫点整体布局,规范引导免疫行为和内部运行。     

Diagnosing feline immunodeficiency virus (FIV) infection in FIV-vaccinated and FIV-unvaccinated cats using saliva

We recently showed that two immunochromatography point-of-care FIV antibody test kits (Witness FeLV/FIV and Anigen Rapid FIV/FeLV) were able to correctly assign FIV infection status, irrespective of FIV vaccination history, using whole blood as the diagnostic specimen. A third FIV antibody test kit, SNAP FIV/FeLV Combo (an enzyme-linked immunosorbent assay [ELISA]), was unable to differentiate antibodies produced in response to FIV vaccination from those incited by FIV infection. The aim of this study was to determine if saliva is a suitable diagnostic specimen using the same well characterized feline cohort. FIV infection status of these cats had been determined previously using a combination of serology, polymerase chain reaction (PCR) testing and virus isolation. This final assignment was then compared to results obtained using saliva as the diagnostic specimen utilizing the same three point-of-care FIV antibody test kits and commercially available PCR assay (FIV RealPCR). In a population of cats where one third (117/356; 33%) were FIV-vaccinated, both immunochromatography test kits accurately diagnosed FIV infection using saliva via a centrifugation method, irrespective of FIV vaccination history. For FIV diagnosis using saliva, the specificity of Anigen Rapid FIV/FeLV and Witness FeLV/FIV was 100%, while the sensitivity of these kits was 96% and 92% respectively. SNAP FIV/FeLV Combo had a specificity of 98% and sensitivity of 44%, while FIV RealPCR testing had a specificity of 100% and sensitivity of 72% using saliva. A revised direct method of saliva testing was trialed on a subset of FIV-infected cats (n = 14), resulting in 14, 7 and 0 FIV positive results using Anigen Rapid FIV/FeLV, Witness FeLV/FIV and SNAP FIV/FeLV Combo, respectively. These results demonstrate that saliva can be used to diagnose FIV infection, irrespective of FIV vaccination history, using either a centrifugation method (Anigen Rapid FIV/FeLV and Witness FeLV/FIV) or a direct method (Anigen Rapid FIV/FeLV). Collection of a saliva specimen therefore provides an acceptable alternative to venipuncture (i) in fractious cats where saliva may be easier to obtain than whole blood, (ii) in settings when a veterinarian or trained technician is unavailable to collect blood and (iii) in shelters where FIV testing is undertaken prior to adoption but additional blood testing is not required.     

Suppression of behavioural and physiological oestrus in the mare by vaccination against GnRH

OBJECTIVE: To examine the immunogenicity of an equine immunocontraceptive vaccine and its efficacy in controlling hormone-related behaviour. DESIGN: A total of 24 mares at two sites in Australia were vaccinated with an immunocontraceptive vaccine comprising gonadotrophin releasing hormone (GnRH) conjugated to a carrier protein in immunostimulating complex as an adjuvant. Twelve animals at each site received a placebo of adjuvant alone and served as controls for seasonal oestrus, hormonal and behaviour patterns. Animals were observed for injection site reactions, ovarian and follicular activity, and serum levels of antibody, 17beta-oestradiol and progesterone in the weeks following vaccination. Mares were also examined for oestrous behaviour by teasing with a stallion. RESULTS: All mares responded to vaccination. Two weeks following the second vaccination there was a peak in antibody response to GnRH that declined gradually over the following weeks. Commensurate with the elevated anti-GnRH antibody there was a marked effect on ovarian activity with a reduction in 17beta-oestradiol and progesterone levels in the 24 vaccinated mares. There was also a reduction of oestrus-related behaviour as determined by a teaser stallion. This effect lasted a minimum of 3 months and correlated with the initial level of antibody response. CONCLUSION: Following a conventional two-dose immunisation regime this commercially available equine immunocontraceptive vaccine was effective at inhibiting oestrous behaviour for at least 3 months. This vaccine has a high level of safety since there were no significant local reactions nor were there any adverse systemic responses to vaccination.