人甲型H7N9禽流感全病毒灭活疫苗和裂解疫苗在小鼠中的免疫原性研究

 目的   比较人甲型H7N9禽流感全病毒灭活疫苗和裂解疫苗在小鼠中的免疫原性,为该疫苗的类型选择提供初步依据。 方法   采用相同血凝素含量（5 μg）的H7N9全病毒灭活和裂解疫苗（含或不含氢氧化铝佐剂共4种类型）,分别对BALB/c小鼠进行1针或2针免疫。免疫后,用血凝抑制（hemagglutination inhibition,HI）试验检测血清抗体滴度,比较不同类型疫苗的免疫效果。 结果   小鼠免疫1针全病毒灭活疫苗后,全部血清阳转,HI抗体几何平均滴度（geometric mean titer,GMT）为149;免疫2针后,抗体GMT为243。小鼠免疫1针裂解疫苗后无抗体阳转;免疫2针后全部抗体阳转,GMT为139。两种疫苗添加铝佐剂后,诱导的HI抗体GMT仅略有增加。 结论   H7N9全病毒灭活疫苗在小鼠中的免疫原性较强。在同样类型和剂量的情况下,裂解疫苗需要免疫两次才能达到与全病毒疫苗相同的效果。铝佐剂对免疫原性提升不明显。     

Local and systemic antibody response to rotavirus WC3 vaccine in adult volunteers

An evaluation of the safety and immunogenicity of WC3 rotavirus vaccine was evaluated in adult volunteers. Pre- and post-vaccination titers of neutralizing antibody to WC3 and to the four human rotavirus serotypes as well as serum and stool rotavirus IgA levels were measured. Vaccination was safe and did not induce elevation of liver enzymes. None of the 12 volunteers receiving WC3 vaccine shed detectable amounts of virus although antibody rises were detected in 11 of 12 vaccines. Nine developed and increase in WC3 neutralizing antibody, one additional subject had a rise in Wa (human serotype 1) neutralizing antibody while another subject only developed a rise in stool rotavirus IgA. All of the vaccine recipients with a rise in WC3 neutralizing antibody also developed a rise in neutralizing antibody against at least one of the four most common human rotavirus serotypes. A stool IgA rotavirus antibody response was detected in 6 of 9 WC3 recipients with measurable stool antibody. None of the control subjects developed significant rises in any of the antibody titers measured. WC3 rotavirus vaccine appears to be safe and induces systemic and local immune responses in adults suggesting that further evaluation of WC3 should be considered in infants.     

Raccoon poxvirus as a mucosal vaccine vector for domestic cats

In the present study, we evaluated both the immunogenicity and safety of recombinant raccoon poxvirus (RCN) as a mucosal vaccine vector for domestic cats. RCN is an orthopoxvirus that was isolated from healthy raccoons and has been used experimentally as a vaccine vector for rabies and other antigens in a variety of species, including raccoons, skunks, foxes, bobcats, rabbits, domestic cats, piglets, sheep and non-human primates. We evaluated the antibody response induced by a recombinant RCN vaccine expressing the rabies-G glycoprotein (RCN/rabies-G) administered to cats by the oral (PO), intranasal (IN), conjunctival (CO) or intranasal/conjunctival (IN/CO) route (dose: 10 plaque forming units or PFU). The IN route, either alone or combined with the CO route, induced the highest rabies virus neutralizing antibody (RVNA) titers. The RVNA titers remained high when measured at six months post-vaccination, demonstrating that the recombinant vaccine administered via these routes is very efficient at inducing long-lasting immunity. A dose-response was observed following IN vaccination in cats. Doses of 10 PFU induced strong antibody responses in 4 of 5 animals [geometric mean titer: 3.2 (log)]. None of the animals vaccinated with 10 PFU developed detectable RVNA titers. In this study, RCN/rabies-G viral shedding was below detectable levels. Nasal, oral and fecal swabs collected from these cats were negative for RCN by both virus isolation and by nested-PCR. In addition, no horizontal transmission of the virus could be detected. Gang-housed sentinel animals for each group did not develop detectable anti-RVNA or -RCN antibodies. To study tissue tropism of recombinant raccoon poxvirus vaccines, a RCN that can express the lacZ gene (RCN/lacZ) was constructed. Expression of beta-galactosidase (beta-gal) was validated in vitro and in mice in vivo. Cats were vaccinated IN with 10 PFU of RCN/lacZ. No histopathological lesions were detected in any of the tissues collected from these cats at 1, 4, 7 and 15 days post-vaccination. In addition, no virus or beta-gal expression was detected in any of these tissues. Controls demonstrated that virus could be reisolated from nasal swabs immediately after administration of 10 PFU to cats. These results suggest that recombinant RCN vaccines undergo limited replication after intranasal administration in cats that is sufficient to elicit strong, long-lasting systemic antibody responses.     

叙利亚地鼠作为狂犬病暴露后免疫动物模型的研究

目的  对叙利亚地鼠（地鼠）作为狂犬病暴露后疫苗免疫效果动物模型的可行性进行研究。方法 将狂犬病病毒CVS株和CTN-1V株分别肌内感染不同周龄的地鼠和小鼠,观察动物对不同毒株的敏感性。用直接免疫荧光法检测CVS株进入地鼠脑组织的情况;用快速荧光灶抑制试验检测血清中和抗体。以不同病毒量CVS株感染8周龄雌性地鼠,确定暴露时病毒的最佳感染剂量。对暴露后地鼠用疫苗进行免疫,观察疫苗的保护效果。结果  地鼠感染后7 d左右出现狂犬病临床症状,同一病毒株对地鼠的致病力比小鼠强〔6.4～8.0 lg半数致死量（LD₅₀）/ml对3.4~6.5 lgLD₅₀/ml〕;3周龄和8周龄地鼠对病毒的敏感性无差异。感染后5~6 d病毒进入地鼠脑组织。以3.8～4.0 lg小鼠脑内半数致死量（MICLD₅₀）/ml的CVS株感染后6～7 d,地鼠血清中检出中和抗体。暴露后疫苗免疫结果显示,不同疫苗具有不同程度的保护效果。结论  地鼠对狂犬病病毒神经外途径感染敏感,临床症状典型,潜伏期恒定,感染后免疫血清抗体应答出现早,具备作为暴露后疫苗免疫动物模型的条件。     

The humoral response to Gardasil over four years as defined by total IgG and competitive Luminex immunoassay

Safe and effective vaccines against anogenital human papillomaviruses (HPV) are now available. These vaccines, composed of virus-like particles (VLPs) made from the L1 major capsid protein of specific HPV types, induce a polyclonal antibody response directed against specific conformational and linear epitopes displayed on the VLP. Numerous studies indicated the importance of neutralizing antibodies in protection from infection. However, our understanding of the antibody responses to these vaccines is not complete, and there is no established immune correlate of protection nor antibody threshold that correlates with protection against HPV infection or disease. In the current study, antibody responses of young women to Gardasil?, the quadrivalent HPV 6, 11, 16 and 18 L1 VLP vaccine (qHPV), were assessed through 48 months (M) in total IgG and competitive Luminex immunoassays (total IgG LIA and cLIA). The total IgG LIA was developed as a research assay to evaluate preclinical multivalent HPV VLP vaccine formulations. The cLIA simultaneously evaluates the antibody response to a unique conformational, neutralizing epitope on each of the four HPV types present in the quadrivalent vaccine; HPV 6, 11, 16 and 18. The same sera from women vaccinated with the qHPV vaccine were tested in both the total IgG LIA and the cLIA assays. The proportion of vaccinated women achieving seropositivity and the anti-HPV VLP total IgG and cLIA geometric mean titers (GMTs) were summarized at M7, M24, M48 based on the serostatus cut-points defined for each immunoassay. Overall, greater than 99% of subjects seroconverted to all four vaccine types in both assays; GMTs peaked at M7. For all four HPV types, regardless of the immunoassay used, the most significant decline in GMTs was observed between M7 and M24. By M24, the antibody titers had reached a plateau and minimal declines in antibody titers were observed between M24 and M48 for all four HPV types in both immunoassays. Testing the same sera, seropositivity for M48 HPV18 remained high (96.7%) in the total IgG LIA, but was 64.8% in the cLIA. The current study illustrates potential important differences in serologic assays utilized in the clinical trials of the two currently available HPV VLP vaccines (quadrivalent and bivalent). Differences in seropositivity status are attributed to the measurement parameters and sensitivity of the individual immunoassays and do not indicate reduced anti-HPV18 protective antibodies.     

Immunogenicity and efficacy of Fermi-type nerve tissue rabies vaccine in mice and in humans undergoing post-exposure prophylaxis for rabies in Ethiopia

Rabies is an acute viral encephalitis that is invariably fatal following the manifestations of clinical signs. To subvert the course of the disease, rabies post-exposure prophylaxis (PEP) is widely utilized. The immunogenicity and efficacy of Fermi-type rabies vaccine produced in Ethiopia was determined in mice subjected to intracranial challenge with rabies virus, and in humans undergoing rabies PEP in Ethiopia. Mice were randomly assigned into 5 groups. Group 1 received 0.25 ml each of phenolized saline intraperitoneally for 14 consecutive days. Mice in groups 2-5 received 0.25 ml of rabies vaccine for human PEP for the same period of time. Blood samples were drawn from the retro-orbital vein of all mice on designated days for the determination of rabies virus neutralizing antibody (VNA) using the mouse serum neutralization test. Mice were subsequently challenged intracranially with rabies virus at a concentration of 64 MICLD50 90 days post initial vaccination. Rabies neutralizing antibody titers in the sera of immunized mice ranged from 4.6 to 25 IU/ml. Booster vaccine doses did not seem to induce significant increases in the immune response of vaccinated mice, all of whom withstood intracranial challenge with rabies virus. Rabies VNA was further determined in 12 patients vaccinated in accordance with the prescribed dosage of Fermi-type vaccine for human rabies PEP. Most had > 0.5 IU/ml of rabies VNA by day 14, and none detectable at day 1. In contrast to mice, booster doses of vaccine may contribute to slightly higher rabies VNA titers in humans but our small sample size, on top of significant defaulter rates in the study participants, limits our interpretation of the effects of booster vaccine doses. The results of this study are the first documentation of the efficacy and immunogenicity of the Ethiopian Fermi type nerve tissue vaccine in both humans and mice.     

Immunization of Mice with Anthrax Protective Antigen Limits Cardiotoxicity but Not Hepatotoxicity Following Lethal Toxin Challenge

Protective immunity against anthrax is inferred from measurement of vaccine antigen-specific neutralizing antibody titers in serum samples. In animal models, in vivo challenges with toxin and/or spores can also be performed. However, neither of these approaches considers toxin-induced damage to specific organ systems. It is therefore important to determine to what extent anthrax vaccines and existing or candidate adjuvants can provide organ-specific protection against intoxication. We therefore compared the ability of Alum, CpG DNA and the CD1d ligand α-galactosylceramide (αGC) to enhance protective antigen-specific antibody titers, to protect mice against challenge with lethal toxin, and to block cardiotoxicity and hepatotoxicity. By measurement of serum cardiac Troponin I (cTnI), and hepatic alanine aminotransferase (ALT), and aspartate aminotransferase (AST), it was apparent that neither vaccine modality prevented hepatic intoxication, despite high Ab titers and ultimate survival of the subject. In contrast, cardiotoxicity was greatly diminished by prior immunization. This shows that a vaccine that confers survival following toxin exposure may still have an associated morbidity. We propose that organ-specific intoxication should be monitored routinely during research into new vaccine modalities.     

Raccoon Poxvirus as a Mucosal Vaccine Vector for Domestic Cats

In the present study, we evaluated both the immunogenicity and safety of recombinant raccoon poxvirus (RCN) as a mucosal vaccine vector for domestic cats. RCN is an orthopoxvirus that was isolated from healthy raccoons and has been used experimentally as a vaccine vector for rabies and other antigens in a variety of species, including raccoons, skunks, foxes, bobcats, rabbits, domestic cats, piglets, sheep and non-human primates. We evaluated the antibody response induced by a recombinant RCN vaccine expressing the rabies-G glycoprotein (RCN/rabies-G) administered to cats by the oral (PO), intranasal (IN), conjunctival (CO) or intranasal/conjunctival (IN/CO) route (dose: 10₈ plaque forming units or PFU). The IN route, either alone or combined with the CO route, induced the highest rabies virus neutralizing antibody (RVNA) titers. The RVNA titers remained high when measured at six months post-vaccination, demonstrating that the recombinant vaccine administered via these routes is very efficient at inducing long-lasting immunity. A dose-response was observed following IN vaccination in cats. Doses of 10₇ PFU induced strong antibody responses in 4 of 5 animals [geometric mean titer: 3.2 (log₁₀)]. None of the animals vaccinated with 10₄ PFU developed detectable RVNA titers. In this study, RCN/rabies-G viral shedding was below detectable levels. Nasal, oral and fecal swabs collected from these cats were negative for RCN by both virus isolation and by nested-PCR. In addition, no horizontal transmission of the virus could be detected. Gang-housed sentinel animals for each group did not develop detectable anti-RVNA or -RCN antibodies. To study tissue tropism of recombinant raccoon poxvirus vaccines, a RCN that can express the lacZ gene (RCN/lacZ) was constructed. Expression of β-galactosidase (β-gal) was validated in vitro and in mice in vivo. Cats were vaccinated IN with 10₇ PFU of RCN/lacZ. No histopathological lesions were detected in any of the tissues collected from these cats at 1, 4, 7 and 15 days post-vaccination. In addition, no virus or β-gal expression was detected in any of these tissues. Controls demonstrated that virus could be reisolated from nasal swabs immediately after administration of 10₈ PFU to cats. These results suggest that recombinant RCN vaccines undergo limited replication after intranasal administration in cats that is sufficient to elicit strong, long-lasting systemic antibody responses.     

Measurement over 1 Year of Neutralizing Antibodies in Cattle Immunized with Trivalent Vaccines Recombinant Alpha,Beta and Epsilon of Clostridium perfringens

The alpha (CPA), beta (CPB) and epsilon (ETX) toxins of Clostridium perfringens are responsible for causing diseases that are difficult to eradicate and have lethal potential in production animals. Vaccination of herds is still the best control strategy. Recombinant clostridial vaccines have shown good success at inducing neutralizing antibody titers and appear to be a viable alternative to the conventional production of commercial clostridial toxoids. Research is still needed on the longevity of the humoral immune response induced by recombinant proteins in immunized animals, preferably in target species. The objective of this study was to measure the humoral immune response of cattle immunized with trivalent vaccines containing the recombinant proteins alpha (rCPA), beta (rCPB) and epsilon (rETX) of C. perfringens produced in Escherichia coli at three different concentrations (100, 200, and 400 µg) of each protein for 12 months. The recombinant vaccines containing 200 (RV2) and 400 µg (RV3) yielded statistically similar results at 56 days. They performed better throughout the study period because they induced higher neutralizing antibody titers and were detectable for up to 150 and 180 days, respectively. Regarding industrial-scale production, RV2 would be the most economical and viable formulation as it achieved results similar to RV3 at half the concentration of recombinant proteins in its formulation. However, none of the vaccines tested induced the production of detectable antibody titers on day 365 of the experiment, the time of revaccination typically recommended in vaccination protocols. Thus, reiterating the need for research in the field of vaccinology to achieve greater longevity of the humoral immune response against these clostridial toxins in animals, in addition to the need to discuss the vaccine schedules and protocols adopted in cattle production.     

The humoral and cell-mediated immune response induced by the NIVGRIP inactivated influenza vaccine

A comparative study was conducted in patients vaccinated with the NIVGRIP trivalent inactivated influenza vaccine and in placebo receiving controls on the kinetics of the serum hemagglutination inhibiting (HAI) antibodies and the neutralizing secretory antibodies in the nasopharyngeal secretions (NPS), of the blastic transformation of lymphocytes index, of the rosette formation index and of the serum immunoglobulins. A significant rise of the H.A.I. and the neutralizing secretory antibodies as well as of the blastic transformation of lymphocytes index was recorded after stimulation with the influenza vaccine. There were no significant changes in controls. No significant variations of the blastic transformation of lymphocytes index after stimulation with P.P.D. and of the rosette formation index were recorded in both investigated groups. Serum immunoglobulin titres showed significant variations in vaccinated as well as in control groups. The results point out the stimulating effect of the NIVGRIP inactivated influenza vaccine on both humoral and cell mediated immune responses.     

重组集成干扰素α在不同动物长期毒性实验血清中中和抗体的产生及活性研究

目的研究重组集成干扰素α在金黄地鼠和猕猴长期毒性实验血清中中和抗体的产生及抗体活性的强弱。方法将金黄地鼠与猕猴分别分为10、30、100μg/kg与1、10、100μg/kg3个剂量组,均每日皮下注射重组集成干扰素α1次,各连续用药60、30d,取给药期和恢复期不同时间的血清,采用细胞病变抑制法进行检测。结果金黄地鼠的30、100μg/kg剂量组与猕猴的3个剂量组从给药第3wk起,在血清中检测到具有中和活性的抗体,抗体滴度在给药第4wk或恢复期第1wk达最高峰,并持续到恢复期结束。其中,猕猴10、100μg/kg剂量组的中和活性高于同期1μg/kg剂量组,10、100μg/kg剂量组之间则无显著性差异(P>0.05),1μg/kg剂量组在恢复期结束时已检测不到中和活性。结论金黄地鼠和猕猴重复注射重组集成干扰素α,血清中均能检测到中和抗体(低剂量组除外),抗体滴度和持续时间与注射剂量呈正相关。     

Protective effect of two recombinant ricin subunit vaccines in the New Zealand white rabbit subjected to a lethal aerosolized ricin challenge: survival, immunological response, and histopathological findings

Ricin, isolated from the castor bean plant Ricinus communis, is included on the Centers for Disease Control and Prevention Category B list of bioterrorism agents, indicating that the toxin is moderately easy to disseminate and could result in moderate morbidity rates. This study evaluated two promising recombinant ricin subunit vaccines, one made using an Escherichia coli codon-optimized gene and the other using a yeast codon-optimized gene in E. coli-based fermentations. Rabbits were vaccinated four times over a period of 6 months and challenged with ～10 to 30 times the median lethal dose of aerosolized ricin. All unvaccinated control rabbits were either found dead or humanely euthanized within 30 h postchallenge, while the rabbits vaccinated with either vaccine survived the exposure without adverse clinical signs. When the protective antibody responses were analyzed, no significant difference was seen between the two vaccines. However, there was a significant difference in the immune response over time for both vaccines tested. Although clinical pathology was unremarkable, significant histological lesions in the control animals included fibrinonecrotic pneumonia, acute necrotizing lesions in the upper respiratory tract, and necrotizing lymphadenitis in the lymph nodes draining the upper and lower respiratory tract. Vaccine-treated rabbits exhibited resolving lesions associated with ricin exposure, namely chronic inflammation in the upper respiratory tract and lungs, fibrosis, type II pneumocyte hyperplasia, and bronchiolitis obliterans. This study confirmed the safety and efficacy of two recombinant ricin subunit vaccines in rabbits, offering potential protection to warfighters and select populations.     

水痘减毒活疫苗无明胶稳定剂的筛选和应用

 目的   研制不含明胶的新型稳定剂,以提高水痘减毒活疫苗的安全性。方法   以现行水痘减毒活疫苗稳定剂配方为基础,去除明胶,配制4种不同的新型稳定剂（B、C、D、E配方）。用无明胶稳定剂制备水痘减毒活疫苗,并将制备的无明胶稳定剂疫苗（B、C、D、E疫苗）与现行的含明胶稳定剂疫苗（作为对照的A疫苗）进行比较,确定最佳稳定剂配方。结果   疫苗成品于37 ℃放置7 d后,A、B、C、D、E疫苗的相关质量指标均符合《水痘减毒活疫苗注册标准》的要求,病毒滴度分别为3.6、3.5、3.3、3.3、3.3 lg PFU/0.5 ml,但C、D、E疫苗的病毒滴度已降至临界值。疫苗成品于2~8 ℃放置24个月后,A、B、C、D、E疫苗的病毒滴度分别为3.4、3.4、3.2、3.0、2.8 lg PFU/0.5 ml,其中C、D、E疫苗的病毒滴度已低于规定的标准（3.3 lg PFU/0.5 ml）,仅B疫苗的相关质量标准符合规定的要求,且与A疫苗（对照）没有差异。 结论   去除明胶的B配方稳定剂对水痘病毒有较好的保护作用。     

Vesicular Stomatitis Virus glycoprotein G carrying a tandem dimer of Foot and Mouth Disease Virus antigenic site A can be used as DNA and peptide vaccine for cattle

Effective Foot and Mouth Disease Virus (FMDV) peptide vaccines for cattle have two major constraints: resemblance of one or more of the multiple conformations of the major VP1 antigenic sites to induce neutralizing antibodies, and stimulation of T cells despite the variable bovine-MHC polymorphism. To overcome these limitations, a chimeric antigen was developed, using Vesicular Stomatitis Virus glycoprotein (VSV-G) as carrier protein of an in tandem-dimer of FMDV antigenic site A (ASA), the major epitope on the VP1 capsid protein (aa 139-149, FMDV-C3 serotype). The G-ASA construct was expressed in the Baculovirus system to produce a recombinant protein (DEL BAC) (cloned in pCDNA 3.1 plasmid) (Invitrogen Corporation, Carlsbad, CA) and was also prepared as a DNA vaccine (pC DEL). Calves vaccinated with both immunogens elicited antibodies that recognized the ASA in whole virion and were able to neutralize FMDV infectivity in vitro. After two vaccine doses, DEL BAC induced serum neutralizing titers compatible with an “expected percentage of protection” above 90%. Plasmid pC DEL stimulated FMDV specific humoral responses earlier than DEL BAC, though IgG1 to IgG2 ratios were lower than those induced by both DEL BAC and inactivated FMDV-C3 after the second dose. DEL BAC induced FMDV-specific secretion of IFN-γ in peripheral blood mononuclear cells of outbred cattle immunized with commercial FMDV vaccine, suggesting its capacity to recall anamnestic responses mediated by functional T cell epitopes. The results show that exposing FMDV-VP1 major neutralizing antigenic site in the context of N-terminal sequences of the VSV G protein can overcome the immunological limitations of FMDV-VP1 peptides as effective protein and DNA vaccines for cattle.     

假病毒在中和抗体检测中的应用研究进展

目前成功的病毒性疫苗大多通过诱导广谱有效的中和抗体来保护机体免受感染,因此检测血清中和抗体水平对疫苗的免疫效果评价具有重要意义.中和抗体检测的传统方法包括微量细胞病变效应抑制法、蚀斑减少试验等,均需进行活病毒操作.近年来,随着逆转录病毒载体和重组病毒表达技术的发展,假病毒得到越来越多的研究,并被广泛应用在新型疫苗研发、中和抗原表位鉴定、细胞嗜性研究、抗病毒药物筛选、中和抗体检测、基因治疗等方面.此文主要对假病毒在中和抗体检测中的应用进行综述,并总结相关领域的研究进展.     

抗柯萨奇病毒A组10型中和抗体检测用毒株的应用研究

目的 研究抗柯萨奇病毒A组10型（Coxsackievirus A10,CV-A10）中和抗体检测用毒株的应用。方法 对CV-A10毒株进行扩增培养,建立3级种子批并进行相关检定。采用3人3次独立测定病毒滴度,对工作种子批进行滴度标定,通过分别与肠道病毒71型（enterovirus A71,EV-A71）、CV-A16、CV-A6免疫血清进行交叉中和反应,评价该毒株的专属性。对CV-A10自然感染人血清和CV-A10小鼠免疫血清样品进行中和抗体效价检测,对其应用进行评价研究。结果 获得一株CV-A10中和抗体检测用毒株,3级种子批的无菌检查、支原体检查等项目均符合中国药典2020年版三部相关要求;经标定,平均病毒滴度为7.903 lg半数细胞培养物感染量（50% cell culture infectious dose,CCID₅₀）/ml（95%置信区间：7.868~7.937 lgCCID₅₀/ml）,变异系数为1.10%;与EV-A71、CV-A16、CV-A6免疫血清无交叉反应,专属性良好;检测CV-A10自然感染人血清和CV-A10小鼠免疫血清,中和抗体的最大值与最小值倍数差均小于4,中和抗体检测变异系数分别为6.38%和3.64%。结论 抗CV-A10中和抗体检测用毒株具有较好的专属性可很好的应用于后续抗CV-A10中和抗体的相关检测。     

Immunogenicity of a scalable inactivated rotavirus vaccine in mice

Inactivated rotavirus vaccine is a safe and effective potential vaccine for the prevention of rotavirus infection among children, but no approved licensed vaccine is available now. In this study, a scalable inactivated rotavirus vaccine, prepared in Vero cells cultured by microcarrier fermentation, inactivated by formalin and absorbed by Al(OH)(3) adjuvant, was vaccinated into the six weeks-old female Balb/c mice by intramuscular injection. After twice immunization at interval of three weeks, both humoral and cell-mediated immune responses were assessed by ELISA, microneutralization assay and EISPOT assay. The results indicated that the scalable inactivated rotavirus vaccines induced not only high serum IgG antibody and neutralizing antibody responses, but Th1 and Th2 cytokine-secreting cell responses in mice immunized by the inactivated rotavirus vaccines. These results suggest that the scalable inactivated rotavirus vaccine has good immunogenicity, which provided the base for the scaled development of inactivated rotavirus vaccine in the future.     

Serum and Intestinal Antitoxin Antibody Responses after Immunization with the Whole-Cell/Recombinant B Subunit (WC/rBS) Oral Cholera Vaccine in North American and Mexican Volunteers

Background: Immune protection against cholera infection is probably mediated in part by locally produced, intestinal secretory IgA (sIgA) antibodies. We study the kinetics of intestinal (sIgA) and systemic (serum IgG) antitoxin antibody responses after immunization with whole-cell/recombinant B subunit oral cholera vaccine (WC/rBS) in U.S. travelers to Mexico and Mexican volunteers.
Methods: Two doses of WC/rBS were administered 10 days apart to ten U.S. adults, newly arrived in Mexico, and 18 Mexican nationals. Serum IgG and intestinal secretory IgA (sIgA) antibodies to the B subunit of cholera toxin were measured from day 0 to day 21 by a direct enzyme-linked immunosorbent assay (ELISA).
Results: Positive serum IgG responses to vaccination were detected in 80% of U.S. adults and in 59% of Mexican adults. All volunteers, regardless of nationality, developed a positive sIgA antibody response to WC/rBS. No differences were observed between U.S. and Mexican volunteers in the magnitude and kinetics of serum IgG responses. We recorded differences in the kinetics of sIgA antibody, with early and late peak sIgA antitoxin responses demonstrated in the Mexican and U.S. volunteer groups, respectively. Although the presence or absence of antitoxin sIgA antibodies prevaccination (sIgA titer > 1:4) did not interfere with the final postimmunization magnitude of the antibody responses (sIgA measurements days 14 and 21), the initial measurement curves showed differences (sIgA measurements days 0 and 3).
Conclusions: The WC/rBS vaccine stimulated antitoxin antibody formation both in serum and locally in the intestine. The presence or absence of specific sIgA antibodies prevaccination did not seem to interfere with the magnitude of the antibody responses postvaccination (days 14, 21). The measurement of sIgA responses in fecal extracts appears to provide a simple and sensitive method to assess the intestinal immune response to orally administered vaccines.     

Single immunization with a recombinant multiple-epitope protein induced protection against FMDV type Asia 1 in cattle

To develop recombinant epitope vaccines against the foot-and-mouth disease virus (FMDV) serotype Asia 1, genes encoding six recombinant proteins (A1–A6) consisting of different combinations of B-cell and T-cell epitopes from VP1 capsid protein (VP1) of FMDV were constructed. These proteins were expressed in Escherichia coli and used to immunize animals. Our results showed that A6 elicited higher titers of neutralizing antibodies after single inoculation in guinea pigs than did the other five recombinant proteins, as determined by micro-neutralization tests. In addition, a strong lymphocyte proliferation response and Th1 type immunity were observed in splenocytes from the mice immunized with A6. Further tests carried out in cattle demonstrated that a single inoculation with A6 generated comparable levels of neutralizing antibodies as inactivated vaccine and protected 4 of 5 cattle against challenge with FMDV type Asia 1. Our results suggest that A6 might be a promising recombinant vaccine against FMDV type Asia 1 in cattle.     

鼠疫疫苗在食蟹猴模型中的免疫学评价

目的 通过将鼠疫耶尔森菌的F1抗原和重组V抗原组成的鼠疫疫苗免疫食蟹猴,对疫苗的免疫效果进行评价.方法 将20只食蟹猴按简单随机法分成低剂量组、高剂量组和生理盐水对照组,分别于0和2周肌内免疫,并于1剂后2周和2剂后2周采血.用ELISA检测免疫动物血清中的总IgG抗体;另外,分离外周血淋巴细胞,用酶联免疫斑点试验检测分泌IFN-γ的外周血淋巴细胞.用t检验对结果进行比较.结果 免疫后,对照组均未产生抗体,而疫苗组产生了较强的抗体应答.2剂免疫后2周,低、高剂量组的抗F1抗原IgG抗体几何平均滴度分别为(4.71±0.32)1g和(5.09±0.21)lg(t=-2.76,P＜0.05),两组的抗重组V抗原IgG抗体几何平均滴度分别为(4.75±0.52) lg和(5.12±0.58) lg(t=-1.37,P＞0.05).经F1和V抗原体外刺激产生IFN-γ的外周血淋巴细胞,细胞数均无明显增加.F1抗原刺激后,低、高剂量组分泌IFN-γ的外周血淋巴细胞数分别为(1±1)/106和(1±2)/106(t=-0.16,P＞0.05).重组V抗原刺激后,两组分别为(7±15)/106和(6±7)/106(t=0.88,P＞0.05).结论 鼠疫疫苗在食蟹猴模型中能诱导较强的体液免疫应答,但不能诱导明显的细胞免疫应答.