国产与进口冻干无佐剂人用狂犬病疫苗的安全性和免疫原性比较

目的评价国产冻干人用无佐剂狂犬病纯化疫苗(Vero细胞)的安全性和免疫原性。方法对600名健康人随机分为两组,480人(A组)接种冻干无佐剂人用狂犬病纯化疫苗(Vero细胞)和120人(B组)作为对照接种巴斯德公司生产的冻干无佐剂狂犬病纯化疫苗,采用0、3、7、14和28天免疫程序。观察每针次接种后72小时内局部和全身反应及14天、45天的免疫应答水平。结果所有接种对象均未出现严重局部和全身副反应。首剂免疫14天,A、B组抗体阳性率分别均达到98.06%和96.49%,几何平均滴度为5.0IU/ml和3.79IU/ml。免疫后45天,A、B组抗体阳性率均达到100%,抗体几何平均滴度分别上升至7.97IU/ml和7.61IU/ml。结论国产人用狂犬病无佐剂纯化疫苗(Vero细胞)具有良好安全性和免疫原性。     

Expression in plants and immunogenicity of plant virus-based experimental rabies vaccine

A new approach to the production and delivery of vaccine antigens is the use of engineered amino virus-based vectors. A chimeric peptide containing antigenic determinants from rabies virus glycoprotein (G protein) (amino acids 253-275) and nucleoprotein (N protein) (amino acids 404-418) was PCR-amplified and cloned as a translational fusion product with the alfalfa mosaic virus (AlMV) coat protein (CP). This recombinant CP was expressed in two plant virus-based expression systems. The first one utilized transgenic Nicotiana tabacum cv. Samsun NN plants providing replicative functions in trans for full-length infectious RNA3 of AlMV (NF1-g24). The second one utilized Nicotiana benthamiana and spinach (Spinacia oleracea) plants using autonomously replicating tobacco mosaic virus (TMV) lacking native CP (Av/A4-g24). Recombinant virus containing the chimeric rabies virus epitope was isolated from infected transgenic N. tabacum cv. Samsun NN plants and used for parenteral immunization of mice. Mice immunized with recombinant virus were protected against challenge infection. Based on the previously demonstrated efficacy of this plant virus-based experimental rabies vaccine when orally administered to mice in virus-infected unprocessed raw spinach leaves, we assessed its efficacy in human volunteers. Three of five volunteers who had previously been immunized against rabies virus with a conventional vaccine specifically responded against the peptide antigen after ingesting spinach leaves infected with the recombinant virus. When rabies virus non-immune individuals were fed the same material, 5/9 demonstrated significant antibody responses to either rabies virus or AlMV. Following a single dose of conventional rabies virus vaccine, three of these individuals showed detectable levels of rabies virus-neutralizing antibodies, whereas none of five controls revealed these antibodies. These findings provide clear indication of the potential of the plant virus-based expression systems as supplementary oral booster for rabies vaccinations.     

Potency requirements of rabies vaccines administered intradermally using the Thai Red Cross regimen: investigation of the immunogenicity of serially diluted purified chick embryo cell rabies vaccine

To determine the minimum vaccine potency per intradermal dose required to elicit an adequate immune response using the Thai Red Cross (TRC) regimen (2-2-2-0-1-1), healthy volunteers received 0.1 mL volumes of PCECV containing decreasing amounts of antigen. Subjects also received HRIG to evaluate potential interference with antibody production. Results indicated that when each 0.1 mL intradermal dose of PCECV contained antigen corresponding to 0.32 IU per intramuscular dose, every subject had titers above 0.5 IU/mL by day 14. These results confirm that the current World Health Organization (WHO) recommendations for vaccine potency (2.5 IU per intramuscular dose) are sufficient for use in the Thai Red Cross intradermal regimen.     

Safety and immunogenicity of human rabies vaccine for the Chinese population after PEP: A systematic review and meta-analysis

AimTo evaluate the safety and immunogenicity of rabies vaccine for human use after post-exposure in China. Methods: A systematic search was performed from PubMed, EMBASE, CNKI and Cochrane Library database, supplemented by manual retrieval. According to the inclusion and exclusion criteria, a meta-analysis was performed using Stata 16.0 software after independent literature screening, data extraction and quality assessment by two evaluators. Results: A total of 32 studies were included. It was found that rabies vaccination after PEP could induce the body to produce sufficient RVNA. Both Essen and Zagreb regimens showed good immunogenicity, with no significant difference in systemic events and local events after PEP, but a relatively high incidence of local and systemic events after PEP under the Zagreb regimen. Conclusion: For the Chinese population, rabies vaccination after PEP has shown relatively a good immune efficacy and acceptable safety for preventing human rabies. The survey also found that the Zagreb regimen was comparable to the Essen regimen in terms of rabies prophylaxis with an acceptable safety profile.     

一种国产人用狂犬病疫苗(Vero细胞)的免疫原性与安全性评价

目的 评价一种国产人用狂犬病疫苗(Vero细胞)用于10～60岁健康人群的免疫原性和安全性。 方法 单中心、随机、双盲、同类制品平行对照、模拟暴露后免疫的非劣效性研究。采用“Essen”免疫程序,选择10～60岁健康人群,按照1∶1比例随机接种试验疫苗和对照疫苗,使用日记卡收集每针次接种后不良反应情况。采集免前、首针免后第14天和第42天血液标本,用快速荧光灶抑制试验(RFFIT)检测血清中狂犬病毒中和抗体水平。 结果 试验组和对照组各入组600人。首针免后第42天和第14天,抗体阳转率均达到100%;抗体几何平均浓度(GMC)试验组为13.00IU/ml和7.89IU/ml,对照组为15.03IU/ml和10.20IU/ml,差异有统计学意义。总体征集性不良反应发生率试验组和对照组分别为60.33%和65.67%,差异无统计学意义。总体全身不良反应发生率对照组(46.17%)高于试验组(39.83%),前3针次不良反应发生率对照组(25.17%、16.13%、27.97%)均高于试验组(17.83%、11.80%、22.24%),差异有统计学意义。 结论 长春卫尔赛生物药业有限公司研制的人用狂犬病疫苗(Vero细胞)在10～60岁健康人群中具有较好的免疫原性和安全性。     

Comparison of immunogenicity,efficacy and transcriptome changes of inactivated rabies virus vaccine with different adjuvants

Adjuvants have been proven to be very effective in enhancement of immune response of many antigens. However, few studies involved head-to-head comparison of their potentials in inactive rabies virus vaccine. In this study, we investigated two types of aluminum adjuvants and five other adjuvants (BLPs, AS02, AS03, MF59 and Poly I:C) on their capacity in enhancing the efficacy of rabies vaccine. The differences in immunogenicity and potency of rabies vaccines with different adjuvants were evaluated by immunizations in ICR mice. Compared with other adjuvants, nano-sized aluminum induced earlier and more vigorous production of rabies virus neutralizing antibodies and facilitated a more effective protection in the challenge test. Based on these results, to comprehensively and systematically explore the role of adjuvants in rabies vaccine immunization, blood samples from four groups were chosen to perform mRNA sequencing. The differentially expressed genes (DEGs) of groups were identified, both gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses were conducted for these DEGs. The results showed that there were significant differences in mRNA expression between the mice after immunization with different adjuvants, but the two aluminum adjuvant vaccines induced similar gene expression. Moreover, the data of enrichment analysis indicated that adjuvants were more advantageous in activating the pathways associated with antigen processing, presentation and initial immunity. These results revealed that adjuvants can be used as an enhancer in rabies vaccination, and nano-sized aluminum may be a candidate adjuvant for the development of more effective rabies vaccines. And these data also provide a basis for understanding the mechanisms underlying adjuvants enhancement of the immune response.     

Safety and immunogenicity, after nasal application of HIV-1 DNA gagp37 plasmid vaccine in young mice

BACKGROUND: There is a need for safe and potent adjuvants capable of delivering vaccine candidates over the mucosal barrier, with good capacity to stimulate both mucosal and systemic cell-mediated and humoral immunity. An adjuvant aimed for intranasal delivery should preferably deliver the antigen and minimize the transfer into the close proximity of the central nervous system, thus avoiding damage on the olfactory tissues. Advantages with a mucosal delivery route would be to provide mucosal and systemic immunity, requiring lower vaccine doses then when given parentally. The aim of this study was to study if the N3 adjuvant intranasally administered with HIV DNA plasmids would be transferred into the olfactory tissues and cause local inflammation and tissue damage. RESULTS: The N3 adjuvant alone and when combined with HIV-1 DNA gag plasmid and delivered intranasally did not cause detectable damage to the nasal epithelium or the olfactory epithelium or bulb over a period of 3 days after delivery. The intranasal administration of HIV-1 gagp37 DNA induced both a humoral and a cell-mediated immunity against the gag antigen. Significantly higher HIV-1-specific humoral, but not cell-mediated immune responses were seen in DNA/N3-immunized mice in comparison with HIV-1 DNA/saline-immunized animals. CONCLUSIONS: A safe and convenient intranasal mode of HIV-1 DNA plasmid and adjuvant delivery was shown not to interfere with the tissues in close proximity to the central nervous system. The N3 adjuvant combined with HIV-1 plasmids enhances the HIV-1-specific immunogenicity and merits to be clinically tested.     

人用狂犬病无佐剂纯化疫苗的安全性与免疫原性的初步观察

目的评价国产人用狂犬病无佐剂纯化疫苗(Vero细胞微载体)的安全性和免疫原性。方法对502人(A组)接种人用狂犬病无佐剂纯化疫苗(Vero细胞微载体)另100人(B组)作为对照接种巴斯德公司生产的狂犬病纯化疫苗。采用0、3、7、14和28天程序,观察每针次接种后72小时内局部和全身反应及14天、45天的免疫应答水平。结果所有接种对象均未出现严重局部和全身副反应。首剂免疫14天,A、B组抗体阳性率均达到100%,几何平均滴度为5.2IU/ml和5.6IU/ml。第45天,A组抗体几何平均滴度上升至9.5IU/mll,与B组相似(9.8IU/ml)。结论人用狂犬病无佐剂纯化疫苗(Vero细胞微载体)具有良好安全性和免疫原性。     

Two-year comparative trial on the immunogenicity and adverse effects of purified chick embryo cell rabies vaccine for pre-exposure immunization

The human diploid cell rabies vaccine (HDCV) has been shown to be highly immunogenic when used for pre-exposure immunization. However, the high cost of the product and the adverse reactions seen following booster doses of HDCV have limited its use. A purified chick embryo cell (PCEC) rabies vaccine was compared with the HDCV by two routes of administration for reactogenicity, antibody response, duration of antibody, and anamestic response to boosters over a 2 year period. The study showed that the two vaccines were comparable in their immunogenicity and reactogenicity after initial three dose series. No adverse reactions were noted following the 2 year booster with PCEC. The PCEC can be produced at less than one-half the cost of the HDCV.     

An evaluation of second generation tissue culture rabies vaccines for use in man: a four-vaccine comparative immunogenicity study using a pre-exposure vaccination schedule and an abbreviated 2-1-1 postexposure schedule

In a double-blind comparative trial the immunogenicity of three new tissue culture rabies vaccines was evaluated, using a commercial human diploid cell vaccine (HDCV) lot as the reference. Two different vaccination regimens, a pre-exposure schedule, and an abbreviated 2-1-1 postexposure schedule (two doses of the vaccine applied bilaterally on day 0, with subsequent single doses given on days 7 and 21) were employed. In both, two of the new vaccines, purified chick embryo cell vaccine and purified Vero rabies vaccine, induced an antibody response equivalent to that of HDCV, while the geometric mean titres for the fetal bovine kidney cell vaccine were somewhat lower. The 2-1-1 regimen, a candidate regimen for economical rabies postexposure treatment, evoked a rapid and high titre antibody response with all four vaccines, peaking on day 14.     

Interaction of rabies vaccine with human rabies immunoglobulin and reliability of a 2-1-1 schedule application for postexposure treatment

Five commercially available rabies vaccines (HDCV, FBKC vaccine, PCEC vaccine, PVRV and PDEV) applied alone or combined with human rabies immunoglobulin (HRIG) were administered, by random allocation, to 161 volunteer vaccinees, using the abbreviated 2-1-1 postexposure immunization schedule. Protective levels of rabies antibody were demonstrated in all vaccinees by day 14, and in all but one vaccinee from day 21 to day 90. Partial inhibition of the antibody response due to HRIG was observed for three vaccines (PCEC vaccine, PVRV and PDEV). In terms of economy, reliability and rapid antibody induction, the 2-1-1 schedule proves superior to the presently recommended regimen for postexposure rabies prophylaxis.     

Safety and immunogenicity of WRSd1, a live attenuated Shigella dysenteriae type 1 vaccine candidate

Among Shigella serotypes Shigella dysenteriae type 1 produces the most severe disease, including cases of hemolytic-uremic syndrome and pandemic outbreaks. WRSd1 is a live S. dysenteriae 1 strain attenuated by deletion of the virG(icsA) gene, which encodes a protein that mediates intercellular spread, and stxA and stxB, which encode the Shiga toxin. In this Phase I trial five groups of eight subjects ingested escalating doses of WRSd1 ranging from 10(3) to 10(7)CFU. No subject experienced fever or shigellosis, but 20% had diarrhea. Approximately two-thirds of subjects developed an IgA-ASC response to LPS. Days of fecal shedding of the vaccine strain, but not dose ingested, correlated with stronger immune responses. These results suggest that to be effective an attenuated Shigella vaccine must colonize well.     

One-year study of the 2-1-1 intramuscular postexposure rabies vaccine regimen in 100 severely exposed Thai patients using rabies immune globulin and Vero cell rabies vaccine.

The 2-1-1 rabies postexposure treatment schedule is an abbreviated regimen in which a tissue culture rabies vaccine is administered intramuscularly at two sites on day 0, and at one site on days 7 and 21. Compared to the standard five-dose intramuscular regimen, the 2-1-1 schedule reduces the number of clinic visits from five to three and the amount of vaccine used by 20%. One hundred Thai patients, who were severely exposed to rabies, were treated with rabies immune globulin and the 2-1-1 regimen using purified Vero cell rabies vaccine. They were followed for 1 year. Rabies antibody titres were measured in 10% of this group. All patients survived and adverse reactions were mild. A satisfactory antibody response (a titre greater than 0.5 IU ml-1) occurred in all ten patients studied at day 14, but persisted for 90 days in 80% and for 360 days in only 50%. The authors therefore do not recommend use of the 2-1-1 schedule in severely exposed patients who also need to receive rabies immune globulin.     

Infectivity of attenuated poxvirus vaccine vectors and immunogenicity of a raccoonpox vectored rabies vaccine in the Brazilian Free-tailed bat (Tadarida brasiliensis)

Bats (Order Chiroptera) are an abundant group of mammals with tremendous ecological value as insectivores and plant dispersers, but their role as reservoirs of zoonotic diseases has received more attention in the last decade. With the goal of managing disease in free-ranging bats, we tested modified vaccinia Ankara (MVA) and raccoon poxvirus (RCN) as potential vaccine vectors in the Brazilian Free-tailed bat (Tadarida brasiliensis), using biophotonic in vivo imaging and immunogenicity studies. Animals were administered recombinant poxviral vectors expressing the luciferase gene (MVA-luc, RCN-luc) through oronasal (ON) or intramuscular (IM) routes and subsequently monitored for bioluminescent signal indicative of viral infection. No clinical illness was noted after exposure to any of the vectors, and limited luciferase expression was observed. Higher and longer levels of expression were observed with the RCN-luc construct. When given IM, luciferase expression was limited to the site of injection, while ON exposure led to initial expression in the oral cavity, often followed by secondary replication at another location, likely the gastric mucosa or gastric associated lymphatic tissue. Viral DNA was detected in oral swabs up to 7 and 9 days post infection (dpi) for MVA and RCN, respectively. While no live virus was detected in oral swabs from MVA-infected bats, titers up to 3.88 x 10⁴ PFU/ml were recovered from oral swabs of RCN-infected bats. Viral DNA was also detected in fecal samples from two bats inoculated IM with RCN, but no live virus was recovered. Finally, we examined the immunogenicity of a RCN based rabies vaccine (RCN-G) following ON administration. Significant rabies neutralizing antibody titers were detected in the serum of immunized bats using the rapid fluorescence focus inhibition test (RFFIT). These studies highlight the safety and immunogenicity of attenuated poxviruses and their potential use as vaccine vectors in bats.     

Enhancement of HIV-1 DNA vaccine immunogenicity by BCG-PSN,a novel adjuvant

Although the importance of DNA vaccines, especially as a priming immunization has been well established in numerous HIV vaccine studies, the immunogenictiy of DNA vaccines is generally moderate. Novel adjuvant is in urgent need for improving the immunogenicity of DNA vaccine. Polysaccharide and nucleic acid fraction extracted by hot phenol method from Mycobacterium bovis bacillus Calmette-Guérin, known as BCG-PSN, is a widely used immunomodulatory product in China clinical practice. In this study, we evaluated whether the BCG-PSN could serve as a novel adjuvant of DNA vaccine to trigger better cellular and humoral immune responses against the HIV-1 Env antigen in Balb/C mouse model. The BCG-PSN was mixed with 10 μg or 100 μg of pDRVI1.0gp145 (HIV-1 CN54 gp145 gene) DNA vaccine and intramuscularly immunized two or three times. We found that BCG-PSN could significantly improve the immunogenicity of DNA vaccine when co-administered with DNA vaccine. Further, at the same vaccination schedule, BCG-PSN co-immunization with 10 μg DNA vaccine could elicit cellular and humoral immune responses which were comparable to that induced by 100 μg DNA vaccine alone. Moreover, our results demonstrate that BCG-PSN can activate TLR signaling pathways and induce Th1-type cytokines secretion. These findings suggest that BCG-PSN can serve as a novel and effective adjuvant for DNA vaccination.