Clinical Trial of Measles and Rubella Combined Vaccine Produced by POLYVAC in Vietnam

A clinical trial of measles and rubella combined vaccine (MR: MRVAC) produced by POLYVAC was conducted in Vietnam in 2016. A total of 756 subjects were enrolled, and 504 were allocated to MRVAC and 252 to control MR vaccine groups. Paired sera were obtained in 733, and the number of subjects was 403 aged 1 - 2 years, 164 aged 2 - 18 years, and 166 aged 18 - 45 years. Antibodies against measles and rubella viruses were evaluated by EIA. Most subjects had been immunized with a single dose of Expanded Programme on Immunization (EPI) measles vaccine at 9 months of age. Only 41 of 403 subjects aged 1 - 2 years were negative for measles antibody before vaccination, and all became seroconverted. A serological response of more than a 2-fold increase against measles was noted in 214 (47%, 95% CI;42.4% - 51.6%) of 458 initially seropositive individuals immunized with MRVAC and 65 (28%, 95% CI;22.3% - 33.8%) of 234 in the control group, and geometric mean titer (GMT) after vaccination was 25.49-5.60 in MRVAC and 25.03-5.24 in control group. Seroconversion against rubella virus after immunization with MRVAC was noted in 267 (98.5%, 95% CI;97.1% - 100%) of 271 initially seronegative subjects, similar to that after immunization with control group. GMT after immunization with MRVAC was 24.88-5.11 significantly lower than that after immunization with control vaccine (25.59-5.80). Most subject ≥ 2 years of age had rubella antibody because of MR vaccination campaign and no significant serological response was observed in initially seronegatives. MRVAC was highly immunogenic and safe vaccine and the domestic production of MR vaccine would contribute to realizing the goal of eliminating measles and rubella.

Primary Research of Immunological Mechanism of Combined Hepatitis A-Measles-Varicella Vaccine

To explore the primary humoral and cellular immunological mechanism of the combined hepatitis A-measles-varicella vaccine, the mice were inoculated with hepatitis A-measles-varicella vaccine by intraperitoneally and two weeks later, blood was collected to observe the mice＇s immunological status. Antibody level was measured to appraise the humoral immunity. At the same time, T lymphocyte surface marker, NK cell activity, LAK cell activity, delayed type hypersensitivity of skin, Mφ phagocytic function, mRNA level of cytokine IL-2 and IFN-γ plus lymphocyte transformation test were used to analyze the cellular immunity. The humoral immunity results show that the combined hepatitis A-measles-varicella vaccine produce the same antibody level as their corresponding univalent vaccine, and maintained fine immunogenicity and security. The result of cellular immunity shows that the combined vaccine could activate physical immunocyte, increase the regulative ability of cytokine, enhance the physical immune function and immune defense ability. The present research proved the security and better humoral and cellular immunity of combined hepatitis A-measles-varicella vaccine from the immunological point of view, which laid good foundation for further study and development.

Immunogenicity and Efficacy of Liposome-encapsulated Influenza Split Vaccine in BALB/c Mice

The cellular immunity of current influenza split vaccine is relatively low. It is necessary to develop a novel vaccine to improve the cellular immunity. The authors of this study prepared liposome-encapsulated influenza split vaccine and tested it in BALB/c mice. The mice were immunized once with 4 μg of haemagglutinin of monovalent A/ New Caledonia/20/99 （H1N1 ） encapsulated with liposomes or the split virus vaccine only through intrastomach injection. In a comparative study, it was observed that the liposome-encapsulated vaccine elicited a higher neutralizing antibedy response, more effectively stimulated spleen cell proliferation, increased cell subsets like CD^4＋ and CD^4＋/ CD8^＋ , and triggered IL-4 and IFN-γ production.

Progress in rubella control initiated through measles elimination strategies:the Malaysian experience

Objective:To analyse the laboratory surveillance data from 2004 till 2008 to examine the changing trend of rubella cases in Malaysia.Methods:Samples for this study were either received through the measles case based surveillance program or were hospital cases received for sero-diagnosis of congenital rubella syndrome(CRS). Specific rubella IgM antibody test was carried out on all samples that were negative for measles IgM antibody and for sero-diagnosis of CRS.Results:Through the surveillance program for measles,the samples received for rubella had increased five fold from 365 in 2004 to 1 522 in 2007.Positive rubella cases detected had also increased from 4.1%in 2004 to 33.2%in 2007.The age group 11 to 20 years accounted for 73.6%of rubella cases confirmed in 2008,with a higher incidence among males than females.Positive rubella IgM was detected in 25 CRS cases during the 6 year period between January 2003 and December 2008.Conclusion:The measles elimination program had contributed to significant progress in the control of rubella,with the majority of rubella cases detected through this strategy.Since rubella is not notifiable in Malaysia,this integrated measles and rubella surveillance should be continued.However,to enhance the progress,specific targets should also be established in the national program to eliminate rubella and CRS.

Safety and Antibody Responses to Aerosolized MMR II Vaccine in Adults: An Exploratory Study

Background: There have been no reported studies involving aerosol immunization with 2 of the 3 components of MMR II vaccine—Attenuvax measles vaccine and Jeryl-Lyn mumps vaccine. Objective: To evaluate the safety and antibody responses to aerosolized Attenuvax measles strain, Jeryl Lynn mumps strain and RA 27/3 rubella component of an MMR vaccine in adults, before assessing the booster administration of this vaccine in children. Methods: A pilot study to evaluate safety and antibody responses of MMR II (Merch Sharp & Dhome Corp., Whitehouse Station, NJ 08889, USA) components administered by aerosol was carried out in 27 healthy adults of 21 to 38 years of age. All participants were followed-up during 28 days following immunization for detection of clinical adverse events. Immune response was evaluated by plaque reduction neutralization test for measles, and commercial ELISA kits for rubella and mumps. Results: Only mild clinical adverse events were noted. Despite high levels of baseline seropositivity to all vaccine components, seroresponses to measles, rubella and mumps occurred in 44%, 15% and 41%, respectively. Conclusions: These outcomes compare favorably with earlier studies of other MMR vaccines given by aerosol. Further evaluations on safety and booster immune response should be performed in children.

Relationship between Self-Reported Vaccination History and Measles and Rubella Antibody Titers in Medical and Nursing Students

In hospitals, infection control for measles and rubella is important. Medical and nursing students as well as healthcare workers must have immunity against these diseases. Many countries have adopted requirements for healthcare workers’ documented vaccination history or laboratory tests as evidence of their immunity. Evaluating a written vaccination history is difficult in many cases. Therefore, we compared measles and rubella antibody titers with self-reported vaccination history and we evaluated the association between the history and measles and rubella antibody titers, using the medical and nursing students’ data. We analyzed 564 data for measles and 558 data for rubella. Vaccination history was requested to be completed as accurately as possible. Students with one or more measles or rubella vaccinations had high positive ratios of titer, and the ratio was significantly higher than that of the students without vaccinations. The positive ratio between the two-dose and one-dose vaccination groups was not significantly different for measles or rubella (measles: p = 0.534, rubella: p = 0.452). Although it should be requested that the history is complete by using other resources, such as referring to maternity passbooks or proof of vaccination, self-reported history may be useful to confirm immunity, even if there is a possibility that the history is not accurate.

Reasons of Vaccine Hesitancy among Pakistanis with Available COVID-19 Vaccine: The Next Challenge in the Fight against COVID-19

The government of Pakistan started vaccination campaign for the frontline healthcare pro-viders, as they are more likely to be exposed to COVID-19 patients. In the next step, it ex-tended the free vaccination campaign to include people above 60 and 50 years of age re-spectively. The drive is now open to all citizens >18 years of age. There is a significant re-luctance to get vaccinated even though the government has provided it free of cost. The project uses self-reporting method to assess reasons of vaccine hesitancy among Pakistanis and possible solutions to overcome this problem. Concern for serious side effects was the most common issue 154 (48.42%) reported among all groups of people, including the healthcare workers. The major sources of COVID-19 related information were television 117 (36.8%) and healthcare professionals 105 (33%). The participants reported that they can be convinced to get vaccinated if more published data related to vaccine efficacy and safety is available 118 (37.1%), they observe no side effect among vaccine recipients 90 (28.3%) or higher government officials get the same vaccine 39 (12.3%). Vigorous analysis and publication of data generated is paramount to increase the percentage of people being vaccinated. The healthcare professionals should share evidence-based knowledge related to vaccine efficacy and safety through television and social media to increase acceptance rates and hence, decrease mortality and morbidity from COVID-19 in Pakistan.

Research progress in the off-target effects of Bacille Calmette-Guérin vaccine

Bacille Calmette-Guérin(BCG)vaccine is designed to provide protection against tuberculosis(TB).However,numerous epidemiological,clinical,and immunological studies have shown that BCG vaccination affects neonatal and infant mortality,which may be related to the reduction of TB-unrelated infections and diseases by BCG vaccine.We aimed to discuss the off-target effects of BCG vaccine on un-TB infections and diseases,as well as the potential mechanism and influencing factors.Literature was retrieved mainly from PubMed using medical subject headings"BCG,variations,and non-specific,heterologous or off-target".Studies have showed that BCG vaccination can prevent various heterologous infections,including respiratory tract infections,leprosy,and malaria,treat viral infections including human papillomavirus and herpes simplex virus infection as immunotherapy,and improve the immune responses as vaccine adjuvant.Besides,BCG vaccine can reduce the recurrence rate of non-muscle-invasive bladder cancer,and may provide protection against autoimmune diseases.These off-target effects of BCG vaccine are thought to be achieved by modulating heterologous lymphocyte responses or inducing trained immunity,which were found to be sex-differentiated and affected by the BCG vaccine strains,sequence or time of vaccination.

陕西省渭南市麻疹流行病学特征调查研究

目的:调查分析渭南市麻疹流行病学特征,为麻疹防控提供科学依据。方法:采用描述流行病学方法分析2009—2022年渭南市麻疹疫情监测资料。结果:2009—2022年渭南市累计报告麻疹病例274例,年均发病率0.37/10万。发病呈明显季节性,主要集中在4~6月,占总病例数的61.31%。年平均发病率前三位的区县依次为韩城市(0.78/10万)、潼关县(0.64/10万)和华州区(0.53/10万)。发病年龄主要为0~1岁,占全部病例数的50.73%。发病人群以散居儿童为主(57.30%)。含麻疹成分疫苗(MCV)接种0剂次、1剂次、≥2剂次以及免疫史不详占比依次为34.31%、8.76%、1.82%、55.11%。结论:渭南市近年来麻疹发病率显著降低,2022年发病率达到历史最低水平,但MCV首针及时率及2剂次覆盖率仍需进一步提升。

鸭短喙侏儒综合征亚单位疫苗安全性及免疫效果评价

旨在评价鸭短喙侏儒综合征(SBDS)亚单位疫苗(rBac-JS01 VP2株)的免疫效果。将40只产蛋母鸭和4只成年公鸭随机分成2组,每组产蛋母鸭20只和成年公鸭2只,试验组母鸭经颈背侧皮下注射疫苗0.5 mL,阴性对照组母鸭经颈背侧皮下注射PBS 0.5 mL。免疫后2、4和6个月,分别收集各组种鸭鸭蛋并人工孵化,每个阶段任意选择1日龄健康的公、母雏鸭各20只进行SBDS-JS01毒株攻毒,记录攻毒后雏鸭体重和发病情况,并在攻毒后第3、5、7、14、21天采集雏鸭肛拭子检测排毒情况,每组随机剖检2只雏鸭,观察组织病理变化,PCR检测各组病毒分布情况;免疫后2、4、6个月,采集产蛋鸭血液并分离血清,收集鸭蛋并提取、纯化卵黄抗体,采用SBDS-JS01株测定病毒中和抗体效价。结果显示:种鸭免疫后2、4、6个月,所孵雏鸭对SBDS-JS01攻毒保护率分别为100%、95%、90%,观察期各时间段内免疫攻毒组与对照组相比,试验鸭的体重无显著性差异(P>0.05),而非免疫攻毒组试验鸭的体重极显著低于其他各组(P<0.01);雏鸭攻毒后,免疫攻毒组在免疫后2个月所孵雏鸭肛拭子检测均呈阴性,观察期内各时间段组织器官病毒分布均低于非免疫攻毒组;疫苗免疫组在免疫后2、4、6个月血清的SBDSJS01中和抗体效价分别为(10.51±1.59)log_(2)、(9.46±1.27)log_(2)、(8.83±1.15)log_(2),卵黄中和抗体效价分别为(10.12±1.46)log_(2)、(9.37±1.06)log_(2)、(8.49±1.21)log_(2);不同时期的血清中和抗体效价和卵黄中和抗体效价基本一致,升降趋势相同,且与被动免疫攻毒保护水平变化具有很好的相关性。提示:制备的SBDS亚单位疫苗安全性高,免疫效果较好,对SBDS病毒可提供持续有效的保护力。

Viruses and autism: A Bi-mutual cause and effect

Autism spectrum disorder(ASD)is a group of heterogeneous,multi-factorial,neurodevelopmental disorders resulting from genetic and environmental factors interplay.Infection is a significant trigger of autism,especially during the critical developmental period.There is a strong interplay between the viral infection as a trigger and a result of ASD.We aim to highlight the mutual relationship between autism and viruses.We performed a thorough literature review and included 158 research in this review.Most of the literature agreed on the possible effects of the viral infection during the critical period of development on the risk of developing autism,especially for specific viral infections such as Rubella,Cytomegalovirus,Herpes Simplex virus,Varicella Zoster Virus,Influenza virus,Zika virus,and severe acute respiratory syndrome coronavirus 2.Viral infection directly infects the brain,triggers immune activation,induces epigenetic changes,and raises the risks of having a child with autism.At the same time,there is some evidence of increased risk of infection,including viral infections in children with autism,due to lots of factors.There is an increased risk of developing autism with a specific viral infection during the early developmental period and an increased risk of viral infections in children with autism.In addition,children with autism are at increased risk of infection,including viruses.Every effort should be made to prevent maternal and early-life infections and reduce the risk of autism.Immune modulation of children with autism should be considered to reduce the risk of infection.

维氏气单胞菌弱毒株FS12001及其疫苗对异育银鲫的免疫效果

为探究由维氏气单胞菌(Av)弱毒株FS12001制备的疫苗免疫效果,将Av弱毒株FS12001制备活疫苗、灭活疫苗、ISA763A-灭活疫苗和蜂胶-灭活疫苗,腹腔注射免疫异育银鲫,同时设ISA763A佐剂、蜂胶佐剂及0.65%NaCl作为对照组。于免疫后1、3、5、7和14 d经实时荧光定量PCR(qRT-PCR)检测脾脏组织中IgM、IL-1β及LZM的基因表达量;于免疫后7、14、21、28、42和48 d尾静脉采血分离血清,检测IgM抗体水平,测定SOD和LZM酶活性;于免疫28 d后用2株Av强毒株分别攻毒各组实验鱼,连续观察记录7 d,计算各免疫组的相对保护率。结果显示,各免疫组脾脏组织中IgM、IL-1β及LZM的基因表达量高于对照组,且ISA763A-灭活疫苗组和蜂胶-灭活疫苗组的表达量显著高于其他各实验组。各疫苗免疫组血清特异性抗体水平均显著高于0.65%NaCl对照组和佐剂对照组。各疫苗免疫组的LZM活性均在28 d最高,灭活疫苗组、ISA763A-灭活疫苗组及蜂胶-灭活疫苗组SOD活性均在7 d最高。菌株AVCA07攻毒后,活疫苗组、灭活疫苗组、ISA763A-灭活疫苗组和蜂胶-灭活疫苗组的RPS分别为63%、56%、100%和56%;菌株YC170511攻毒后,以上4个免疫组RPS分别为59%、55%、93%和72%。研究表明,用弱毒株FS12001制备疫苗,注射免疫异育银鲫后均可增加脾脏中IgM、IL-1β及LZM的基因表达量,提高血清抗体水平,增强SOD和LZM酶活性,增强其抵抗Av感染的能力。

利用大蜡螟幼虫和小鼠感染模型筛选猪链球菌血清2、3和9型三价灭活疫苗候选菌株

旨在评估临床分离的猪链球菌血清2、3、9型强毒株制备的三价灭活疫苗对小鼠的免疫保护效果。使用大蜡螟幼虫感染模型和小鼠感染模型,从临床分离的猪链球菌中筛选出血清2、3和9型强毒株各1株(SS1803、SS1803024、SS1696),检测其生长曲线和毒力因子。将菌株分别灭活及混合灭活后与佐剂混合,用4×10^(7)CFU、8×10^(7)CFU SS1803、2×10^(8)CFU、5×10^(8)CFU SS1803024、1×10^(8)CFU、5×10^(8)CFU SS1696及三价灭活苗(2×10^(7)CFU SS1803^(+)1.5×10^(8)CFU SS1803024^(+)3×10^(7)CFU SS1696)分别对BALB/c小鼠进行两轮免疫,采集血清检测特异性抗体水平,分别用3种菌株致死剂量攻毒后观察小鼠免疫保护率,同时用亚致死剂量攻毒三价苗免疫组,测定小鼠血、脑、肺、脾的组织载菌量和细胞因子IL-6、IL-12水平,并观察脑、肺、脾、肾中的组织病理变化。结果显示:3株疫苗候选菌株的毒力基因鉴定分别为SS1803:gapdh^(+)/sly^(+)/fbps^(+)/orf2^(+)/mrp^(-)/89K^(-)/gdh^(+)/epf^(+),SS1803024:gapdh^(+)/sly^(+)/fbps^(+)/orf2^(+)/mrp^(-)/89K^(-)/gdh^(+)/epf^(-),SS1696:gapdh^(+)/sly-/fbps^(+)/orf2^(+)/mrp^(-)/89K^(-)/gdh^(+)/epf^(-)。单价和三价疫苗免疫组均能产生对应免疫血清型的IgG抗体,以产生IgG1型抗体为主。三价疫苗免疫组能对2、3、9型3个菌株攻毒分别提供83.3%、66.7%和66.7%的保护率,能显著降低感染后小鼠组织中的载菌量,降低血清炎性因子水平和组织病变程度。本研究筛选临床流行率高的2、3、9型强毒株,联合制备三价灭活疫苗,能够对小鼠提供良好的免疫保护力,为猪链球菌多价疫苗的研发提供新的材料。

真实世界12岁以下儿童接种麻腮风联合减毒活疫苗后30天内单纯性热性惊厥发生风险分析

目的分析甘肃省12岁以下儿童接种麻腮风联合减毒活疫苗(MMR)后30 d内发生单纯性热性惊厥(SFS)特征。方法筛选甘肃省2021年1月1日至2023年12月31日电子病历库中诊断为“热性惊厥”个案,利用病例身份信息匹配甘肃省免疫规划信息系统中该病例的接种信息,采用观察性流行病学方法分析12岁以下儿童出现SFS的流行特征及接种MMR 30 d内SFS发生风险。结果共纳入10614例SFS儿童患者,12岁以下儿童SFS总体发生率为92.42/10万,其中12~24月龄儿童发生率最高,为297.67/10万,男性儿童发生SFS风险高于女性儿童(RR值为1.61,P<0.001)。接种MMR后30 d内发生SFS风险较未接种该疫苗的高(RR值为2.66,P<0.001)。接种第1剂次的发生率(27.98/10万)较第2剂次(18.48/10万)高,12~24月龄儿童在接种第1剂次MMR 6~14 d SFS发生风险较<12月、25月~6岁组高(RR值分别为4.06和2.64,P<0.001)。结论12~24月龄儿童在接种MMR后6~14 d SFS发生风险增加,以12~24月龄儿童最为常见,应高度关注高风险人群并加强对SFS监测。

铜绿假单胞菌oprI基因DNA疫苗及其重组亚单位疫苗免疫效果的评估

为评估铜绿假单胞菌opr I基因DNA疫苗和重组亚单位疫苗对小鼠的免疫效果,本实验将铜绿假单胞菌外膜蛋白编码基因opr I克隆至真核表达载体p CAGGS-HA中构建重组质粒p CAGGS-opr I,经酶切鉴定正确后获得DNA疫苗。同时将opr I基因克隆至原核表达载体p ET32a中构建重组质粒p ET32a-oprI,经酶切鉴定正确后转入大肠杆菌,经IPTG诱导重组Opr I蛋白(rOprI)的表达,采用亲和层析法纯化后以SDS-PAGE检测,结果显示正确表达了r Opr I,且获得了其纯化蛋白,利用其制备重组亚单位疫苗。分别以DNA疫苗和重组亚单位疫苗免疫BALB/c小鼠,并以铜绿假单胞菌的灭活疫苗和外膜蛋白疫苗为对照,采用间接ELISA法检测免疫后不同时间小鼠血清中的抗体水平和血清中IFN-γ、IL-2和IL-4的含量;初免42 d后以铜绿假单胞菌(1.25×109 cfu/mL,100μL/只)对各组小鼠进行攻毒试验,通过测定各疫苗对小鼠的保护率,评估疫苗的保护效果。结果显示,各疫苗诱导的免疫小鼠血清抗体水平和细胞因子含量均显著高于阴性对照组(P<0.05),且重组亚单位疫苗诱导小鼠的抗体水平和IL-4含量均显著高于DNA疫苗(P<0.05),而IFN-γ和IL-2含量则与DNA疫苗无显著差异(P>0.05)。小鼠攻毒试验结果显示,DNA疫苗组、重组亚单位疫苗组、外膜蛋白疫苗组和灭活疫苗组小鼠获得的免疫保护率分别为45%、55%、70%和95%。上述结果首次表明以铜绿假单胞菌opr I基因制备的DNA疫苗和r Opr I重组亚单位疫苗均可诱导小鼠产生体液和细胞免疫应答,并可为小鼠提供对铜绿假单胞菌攻毒的免疫保护效果,但二者的免疫效果还需进一步提高。本研究为铜绿假单胞菌疫苗的研究提供了参考依据。

原核表达技术在动物传染病疫苗生产中的应用

原核表达技术是基因表达中开发最早、使用最广泛的蛋白表达技术。因具有成本低廉,遗传背景清晰,培养周期短,可大量收获等特点,而在动物传染病疫苗的生产中广泛应用。论文主要总结了利用原核表达技术生产动物传染病疫苗时目的基因的选择,宿主菌的选择、以及疫苗的安全性和免疫效力的检测方法,并对原核表达技术在动物传染病疫苗生产中的安全性与制备成本的优势进行了讨论,以期为今后利用原核表达技术研发和生产疫苗提供参考和借鉴。

可溶性微针疫苗的研究进展

微针作为一种高效的经皮免疫方式,可以穿透角质层,在不损害神经血管的情况下,将抗原递送至免疫细胞丰富的真皮层。其中,可溶性微针(dissolving microneedles,dMNs)由于制备简单、操作便捷、载药量大、不产生针尖废弃物等诸多优点而备受关注。本文总结了dMNs疫苗的免疫效果及目前的临床试验进展,同时探讨了dMNs在使用过程中存在的问题并展望未来的研究方向,以期为dMNs疫苗的相关研究提供参考,并推动其实际应用。

呼吸道感染细菌联合疫苗制备及其免疫效果评价

目的探讨呼吸道感染细菌联合疫苗对免疫效果的影响。方法分离培养6种呼吸道感染细菌(溶血性链球菌、流感嗜血杆菌B型、肺炎链球菌、金黄色葡萄球菌、铜绿假单胞菌及肺炎克雷伯菌),制成联合疫苗。根据联合疫苗质量浓度分为对照组(生理盐水)、低水平组(0.1 g/L疫苗)、中水平组(0.3 g/L疫苗)及高水平组(0.5 g/L疫苗)。各组疫苗作用于人外周血单个核细胞,检测外周血单个核细胞增殖活性、淋巴细胞表型的变化及细胞因子水平。各组疫苗作用于SPF级小鼠,测定各组小鼠迟发型超敏反应、脾脏指数、胸腺指数、巨噬细胞吞噬指数及血清溶血素含量。结果人外周血各组单个核细胞增殖活性、γ干扰素、白细胞介素-2水平均随时间延长而升高,且在相同时间,联合疫苗质量浓度越高,各指标水平越高(P<0.05)。与对照组比较,低、中、高水平组单个核细胞CD4+、CD19+水平升高,CD8+水平降低,且随着联合疫苗质量浓度越高,各指标水平变化越明显(P<0.05)。与对照组小鼠比较,低、中、高水平组小鼠迟发型超敏反应、脾脏指数、胸腺指数、吞噬指数、溶血素水平升高,且随着联合疫苗质量浓度越高,各指标水平越高(P<0.05)。结论呼吸道感染细菌联合疫苗有利于提高细胞及体液免疫能力,且联合疫苗质量浓度为0.5 g/L时,可获得的免疫效果最佳。

六种布鲁菌病疫苗对绵羊与山羊免疫效果的比较

为了比较不同布鲁菌病疫苗对乌拉特草原以放牧为主的山羊与绵羊的免疫效果,我们在乌拉特草原6个苏木/镇,随机选取80~100日龄并经过布鲁菌病检测阴性的乌拉特土种绵羊羔385只、二狼山绒山羊羔275只,用6种布鲁菌病疫苗进行免疫效果比对试验。采用琥红平板凝集试验(RBPT)和试管凝集试验(SAT)分别对试验组羊接种疫苗后7、14、21、35、60、120、150、180、210、240、270 d进行转阳率和抗体效价检测;免疫后270 d进行攻毒试验。RBPT和SAT结果显示,M5-90Δ26和S2接种绵羊与山羊后抗体产生快,持续时间长;免疫后攻毒试验结果显示,A19点眼绵羊和A19-ΔVirB12株皮下注射绵羊保护比例均为4/6;M5-90Δ26绵羊皮下注射和ReV.1山羊点眼的保护比例均为4/5;本试验为乌拉特草原建立牛羊免疫无布鲁菌病区筛选理想疫苗,以及为创建全国首个牛羊免疫无布鲁菌病区制定合理的免疫程序提供了科学依据,同时对布鲁菌病疫苗的研制及国内其他地区布鲁菌病防治具有参考价值和指导作用。

猪圆环病毒2型、猪肺炎支原体和猪瘟疫苗不同免疫程序的免疫效果比较分析

为了评估不同免疫策略对猪场免疫效果和经济效益的影响,以确定最佳的疫苗免疫程序,本试验将处于产前1个月的四胎次健康三元母猪随机分为2个组,A组(联合免疫组)母猪于产前27 d联合免疫猪圆环病毒2型基因工程疫苗、猪肺炎支原体灭活疫苗和猪瘟活疫苗(圆柯欣+柯喘宁+稳柯健),其所产仔猪于21日龄联合免疫圆柯欣、柯喘宁和稳柯健;B组(对照组)母猪于产前34和27 d分别免疫稳柯健、猪圆环病毒疫苗和猪肺炎支原体疫苗二联疫苗(圆-支二联疫苗),其所产仔猪于14日龄免疫圆-支二联疫苗,28日龄免疫稳柯健。统计和分析免疫各组临床指标、生产性能和持续性抗体水平。结果显示,免疫疫苗后,2个组的母猪采食情况均正常;2个组的仔猪整体精神状态良好,哺乳情况正常,均未出现咳嗽和喘气等呼吸道疾病。在试验期间内,2个组的母猪的窝产健仔数和仔猪出生健仔均重并无差别。A组和B组的出生至23日龄死淘率、出生至50日龄死淘率分别为3.77%、5.11%和4.07%、5.43%,A组略优于B组。抗体监测结果显示,A组母猪的CSFV和PCV2抗体水平较B组无显著差异(P>0.05);A组仔猪的CSFV抗体阳性率与B组无明显差异(P>0.05),而PCV2抗体水平在免疫早期阶段(21日龄)明显高于B组(P<0.05)。结果表明,猪圆环病毒2型、猪肺炎支原体和猪瘟疫苗可以联合免疫,且免疫后相互之间不干扰。该联合免疫策略在确保免疫效果的同时,简化了疫苗免疫程序,为确定最佳的疫苗免疫程序提供了有价值的临床应用参考。