Comparison of flagellin and an oil-emulsion adjuvant in inactivated Newcastle disease vaccine in stimulation of immunogenic parameters

The present study was designed to investigate the potential application of native (N) and recombinant (truncated modified [tmFliC] and full-length [flFliC]) flagellin proteins along with inactivated Newcastle disease virus (NDV). Fifty six SPF chickens were immunized twice with PBS (control), inactivated NDV (Ag), inactivated NDV/flFliC (AgF), inactivated NDV/tmFliC (AgT), inactivated NDV/N (AgN), commercial vaccine containing Montanide (Vac) and Vac/N (VacN), with a two-week interval. Blood was collected weekly and spleens were harvested after chickens were sacrificed. Interleukin-6 (IL-6) and tumor necrotic factor-α (TNF-α) gene expression in peripheral blood mononuclear cells were analyzed by Real-Time PCR. Antibody response was assessed by haemagglutination inhibition (HI). Cellular activity was quantified by MTT assay. Results showed that the most IL-6 and TNF-α gene expression was observed in AgF group (P < 0.01). The lowest gene expression among vaccinated groups was observed in Ag group for IL-6 and Ag and Vac group for TNF-α. The highest HI titer was observed in Vac, VacN, AgF and AgT groups. The AgF group showed the highest cellular activity (P < 0.01). In conclusion, flagellin-adjuvanted groups showed a pro-inflammatory effect and acted similarly to or better than the Vac group. Hence, flagellin can be proposed as a potential adjuvant for ND vaccine.     

Vaccination with a genotype 1 modified live vaccine against porcine reproductive and respiratory syndrome virus significantly reduces viremia,viral shedding and transmission of the virus in a quasi-natural experimental model

The present study assessed the efficacy of vaccination against genotype 1 porcine reproductive and respiratory syndrome virus (PRRSV) in terms of reduction of the transmission. Ninety-eight 3-week-old piglets were divided in two groups: V (n = 40) and NV (n = 58) that were housed separately. V animals were vaccinated with a commercial genotype 1 PRRSV vaccine while NV were kept as controls. On day 35 post-vaccination, 14 NV pigs were separated and inoculated intranasally with 2 ml of a heterologous genotype 1 PRRSV isolate (“seeder” pigs, SP). The other V and NV animals were distributed in groups of 5 pigs each. Two days later, one SP was introduced into each pen to expose V and NV to PRRSV. Sentinel pigs were allocated in adjacent pens. Follow-up was of 21 days. All NV (30/30) became viremic after contact with SP while only 53% of V pigs were detected so (21/40, p < 0.05). Vaccination shortened viremia (12.2 ± 4 versus 3.7 ± 3.4 days in NV and V pigs, respectively, p < 0.01). The 50% survival time for becoming infected (Kaplan–Meier) for V was 21 days (CI_95% = 14.1–27.9) compared to 7 days (CI_95% = 5.2–8.7) for NV animals (p < 0.01). These differences were reflected in the R value as well: 2.78 (CI_95% = 2.13–3.43) for NV and 0.53 (CI_95% = 0.19–0.76) for V pigs (p < 0.05). All sentinel pigs (10/10) in pens adjacent to NV + SP pens got infected compared to 1/4 sentinel pigs allocated contiguous to a V + SP pen. These data show that vaccination of piglets significantly decrease parameters related to PRRSV transmission.     

鸡新城疫油佐剂灭活疫苗的研究

采用ＮＤ Ｌａｓｏｔａ株为种毒，福尔马林为灭活剂，７号白油为佐剂，吐温８０、司本８０为乳化剂，硫柳汞为防腐剂，高压匀浆泵为乳化工具，研制出ＮＤ油佐剂灭活疫苗。其剂型为双相型（Ｗ／Ｏ／Ｗ），呈稀薄乳状液，粒度为１ｕｍ左右，粘度≤１ｓ，通针性好。４￣８℃有效保存期１年。效力≥７０ＰＤ５０，最早产生免疫时间为１２天（１００％保护），生产中常用免疫剂量为２月龄内每只０．５ｍｌ，２月龄以上每只１．０ｍｌ皮下     

北京动物园圈养绿孔雀新城疫免疫实验研究

通过圈养绿孔雀新城疫免疫实验研究,对疫苗的安全性以及免疫效果进行了评估。单苗实验组结果：低毒活苗LASOTA可以使抗体水平在4LOG2以上的时间持续6个月;灭活油苗可以使抗体水平保持在4LOG2以上8个月。联苗实验组接种LASOTA疫苗同时肌肉注射灭活油苗后,抗体水平保持4LOG2以上15个月,表明圈养绿孔雀宜采用联合疫苗免疫方法。联合疫苗的应用不仅表现在较高抗体水平维持时间较长,低毒活疫苗还有产生黏膜免疫的重要意义。滴鼻或点眼接种LASOTA疫苗,要保证疫苗能够作用于哈氏腺,以激发动物机体产生黏膜免疫。此外免疫接种时机很重要,对该病的预防工作不应在动物机体较高抗体水平的时候进行免疫接种,也不应在动物机体已经失去保护力或隐性感染后盲目接种,应选择绿孔雀在健康无病情况下进行。同时为了有效地控制新城疫,必须加强禽群免疫监测。     

MTT法评价猪口蹄疫合成肽疫苗的细胞免疫应答

为评价猪口蹄疫合成肽疫苗免疫猪后的细胞免疫应答,用含有E、F两种多肽抗原的猪口蹄疫合成肽疫苗免疫猪,二免后两周采血分离猪外周血淋巴细胞,再用E、F两种合成肽及二者混合物对淋巴细胞刺激培养48 h,用MTT法检测特异性T淋巴细胞增殖反应。结果显示,在抗原E、F混合物浓度为50μg/mL时,抗原对免疫组淋巴结细胞的刺激增殖作用显著高于未免疫对照组（P〈0.01）。表明,该猪口蹄疫合成肽疫苗免疫猪能有效引起特异性T淋巴细胞免疫应答。     

鸭传染性浆膜炎疫苗的研究

用从浙江省分离鉴定的鸭疫里氏杆菌RA-J、RA-L菌株研制疫苗，采用改进的液体培养和鸭胚培养工艺，抗原含量分别达120-186亿CFU／ml和280-310CFU／ml，免疫0.5ml/只，2MLD强毒攻击，平均保护率达94.2％（48／52），免疫后第7天保护率达80％（16／20），10天达93.8％（15／16），疫苗在4℃-8℃条件下保存7个半月和1年的保护率达90％和85％。野外扩大试验和临床推广试用236万羽份表明，效果良好。     

灿烂弧菌灭活菌苗对美国红鱼免疫效果的研究

制备灿烂弧菌(Vibrio splendidus)福尔马林灭活菌苗,通过浸泡、注射和口服3种方式接种美国红鱼(Sci-aenops ocellatus),分别在接种免疫后第7、14、21、28、35天采鱼血,检测其血清抗体效价、溶菌酶活力和白细胞吞噬活性;第28天用1.0×108CFU/mL的灿烂弧菌悬液进行攻毒试验,检测菌苗的免疫效果。结果表明,各免疫组血清抗体效价在第21天达到峰值,且浸泡组和注射组的血清抗体效价高于口服组;在35d实验期内,各免疫组的血清溶菌酶活力有明显提高,各浸泡组和注射组于免疫接种后14d显著高于对照组(P<0.05);除浸泡3组外,其余各免疫组的白细胞吞噬百分比(PP)和吞噬指数(PI)在免疫接种后14d均较对照组有显著差异(P<0.05);各组受免鱼对人工攻毒均具有保护作用,以注射2组的免疫保护率最高,达77.8%。