Quantification of two variant strains contained in freeze-dried Japanese BCG vaccine preparation by real-time PCR.

Japanese bacillus Calmette-Guerin (BCG) vaccine preparation contains two types of variant strains, Type I, which has a 22-base-pair deletion in the RD16 region, and Type II, which has an identical sequence to those of other BCG strains. In this study, we established a method to quantify the percentage of variant strain Type II contained in freeze-dried BCG product with real-time PCR. With this method we examined the master seed lot Tokyo 172, two secondary seed lots, Tokyo 172-1 and Tokyo 172-2, which were produced from Tokyo 172, and four commercial lots produced form Tokyo 172-1. Tokyo 172, Tokyo 172-1, and Tokyo 172-2 contained 55.1%, 19.5%, and 3.6% of Type II variant strain, respectively. Commercial lots contained 1.5%, 4.5%, 7.4%, and 4.3% of Type II variant strain, respectively. These results indicated that the two variant strains contained in the master seed lot continued to coexist in subsequently produced lots with a decrease in population of variant strain Type II. This method would be useful for quality control of commercial Japanese BCG vaccine preparations.     

BCG Moreau Rio de Janeiro: an oral vaccine against tuberculosis--review

The vaccine Bacillus of Calmette Guérin (BCG) was originally developed in France as an oral vaccine against tuberculosis. The oral use of this vaccine was replaced by the parenteral route in almost all countries after the Lubeck disaster. In contrast, Brazil retained the oral delivery of the vaccine until the mid-seventies when it was replaced by the intradermal route. This change in route of delivery was mainly secondary to pressure by medical practitioners based on the poor responses of oral immunized subjects to purified protein derivative (PPD) skin tests. Even after the change of route of delivery, Ataulpho de Paiva Foundation continued making the oral vaccine. Currently, BCG Moreau has been described as one of the most immunogenic and with fewer side effects than other BCGs. The genomics, proteomics and vaccine trials for oral BCG Moreau Rio de Janeiro are currently under investigation. In this review, we intend to describe the history of BCG Moreau Rio de Janeiro in Brazil.     

Effect of the method of preparation of Bacille Calmette-Guérin (BCG) vaccine on the properties of four daughter strains

Samples of Bacille Calmette-Guerin (BCG) vaccines from four collaborating production laboratories, each of which had prepared vaccine from four different daughter strains of BCG, had previously been monitored for changes in colony morphology and the present study was undertaken to determine whether the changes observed were reflected in the patterns of protein secretion and lipid content. In the samples examined there was evidence for a correlation between colony morphology and the presence or absence of mycoside B. As the components of BCG that determine virulence and protective immunity are unknown, care must be taken to ensure constancy of the strains during the manufacture of vaccines.     

Contribution of L-alanine dehydrogenase to in vivo persistence and protective efficacy of the BCG vaccine

The tuberculosis (TB) vaccine strain Mycobacterium bovis BCG is unable to utilise alanine and this deficiency is thought to inhibit the growth of the vaccine in vivo and limit vaccine efficacy. In this report we demonstrate that L-alanine catabolism can be conferred on BCG by introduction of the gene encoding L-alanine dehydrogenase (Ald) of Mycobacterium tuberculosis. Restoration of Ald activity did not change the in vivo growth of BCG in macrophages or mice, and protection against aerosol M. tuberculosis infection was not altered by addition of ald to the BCG vaccine. These results demonstrate that the inability to utilise L-alanine is not a contributing factor to the attenuated phenotype of BCG and does not influence the protective efficacy of the vaccine against TB.     

Genome sequence of Mycobacterium bovis BCG Moreau, the Brazilian vaccine strain against tuberculosis

Mycobacterium bovis bacillus Calmette-Guérin (BCG) is the only vaccine available against tuberculosis, and the strains used worldwide represent a family of daughter strains with distinct genotypic characteristics. Here we report the complete genome sequence of M. bovis BCG Moreau, the strain in continuous use in Brazil for vaccine production since the 1920s.     

Influence of BCG vaccine strain on the immune response and protection against tuberculosis

The Bacille Calmette–Guérin (BCG) vaccine has been used for more than 80 years to protect against tuberculosis. Worldwide, over 90% of children are immunized with BCG, making it the most commonly administered vaccine, with more than 120 million doses used each year. Although new tuberculosis vaccines are under investigation, BCG will remain the cornerstone of the strategy to fight the worsening tuberculosis pandemic for the foreseeable future. The recent delineation of genetic differences between BCG vaccine strains has renewed interest in the influence of the vaccine strain on the protective efficacy against tuberculosis. This review critically examines the data from animal and human studies comparing BCG vaccine strains. Although there is good evidence to support the notion that the induced immune response and protection afforded against tuberculosis differs between BCG vaccine strains, currently, there are insufficient data to favour or recommend one particular strain. Identifying BCG strains with superior protection would have a dramatic effect on tuberculosis control at a population level: a small increment in protection provided by BCG immunization will prevent large numbers of cases of severe tuberculosis and deaths, particularly in children.     

冻干水痘减毒活疫苗转瓶生产工艺的建立

应用旋转培养的方法,建立冻干水痘减毒活疫苗的生产工艺。选择长成致密单层的2BS细胞,接种带状疱疹病毒Oka株,待细胞病变达75％以上时,收获病毒液,经超声破碎、离心、澄清,冻干后,按常规检定,疫苗各项检定符合《WHO水痘活疫苗规程》及《冻干水痘减毒活疫苗制造及检定试行规程》要求。与克氏瓶相比,应用旋转培养,不但提高了疫苗单产,降低了牛血清蛋白残留量,而且疫苗质量也保持稳定。     

Whole-genome sequences of four Mycobacterium bovis BCG vaccine strains

Mycobacterium bovis Bacille Calmette-Guérin (BCG) is the only vaccine available against tuberculosis (TB). A number of BCG strains are in use, and they exhibit biochemical and genetic differences. We report the genome sequences of four BCG strains representing different lineages, which will help to design more effective TB vaccines.     

The stability and immunogenicity of a dispersed-grown freeze-dried Pasteur BCG vaccine

The level of antituberculous immunity seems to be related to the number of memory T cells induced. This may vary as a function of the multiplication and persistence of BCG in host tissues. The most important requirements for a BCG vaccine are, therefore, the immunogenicity of the strain, the high proportion of live to dead bacilli, and adequate dispersion and low levels of soluble antigens. The surface-grown Pasteur BCG vaccine contains a very high proportion of bacilli killed by ball-milling and freeze-drying. It also contains clumps and soluble antigens, all factors influencing cell-mediated immune processes and viability control. Therefore, several batches of vaccine were prepared on an industrial scale using one of the most immunogenic strains (French 1173 P2) and grown as dispersed bacilli by a modified cell type culture method. This method provided fully viable, well-dispersed vaccines which have a viability and heat stability superior to that of the classical surface-grown BCG. The immunogenicity was checked by multiplication and persistence in mouse organs and the skin reactivity and tuberculin hypersensitivity in guinea-pigs showed results comparable to those obtained with classical vaccine. Small-scale tests in children showed superior immunogenicity of the dispersed as opposed to the classical vaccine and there was no suppurative adenitis.     

Background of recent JE vaccine issues

In Japan, more than 5,000 patients were reported in 1950, and there have been less than 10 cases annually since 1992. However, Japanese encephalitis virus caused of Japanese encephalitis (JE) are still existed highly and widely in the country, reported by National Institute of Infectious Diseases with serological examination among domestic pig population. JE immunization had been provided to children as category 1 routine immunization in Japan. However, the Ministry of Health, Labor and Welfare (HOHLW) decided not to recommend JE immunization to children as a routine immunization at May 2005. Major reason on this decision was that the Minter of MOHLW certified to pay loss of medical costs for the case of ADEM (acute disseminated encephalomyelopathy) after JE immunization, recognized as adverse events with JE vaccine, although MOHLW stated that the strict scientific evidence was unknown. MOHLW stated also that it is expected Vero cell derived JE vaccine should be replaced with the present mouse brain derived JE vaccine as the next generation, to be able to avoid theoretical possibility of neurological adverse events associated with JE vaccine. Small but increasing number of requests recently to be certified as health injuries on ADEM cases associated with JE immunization is also another reason for MOHLLW's decision. Further, fifth doses of JE vaccine given to children at 14-15 years old as a routine immunization was decided to be discontinued by MOHLW at July 2005, considering present epidemiological situation on JE and JE immunization status in Japan, although four doses has been recommended continuously as routine. The background details on JE vaccine issues decided by MOHLW in 2005 were reviewed on this paper.     

Molecular analysis of genetic differences between Mycobacterium bovis BCG and virulent M. bovis.

The live attenuated bacillus Calmette-Guérin (BCG) vaccine for the prevention of disease associated with Mycobacterium tuberculosis was derived from the closely related virulent tubercle bacillus, Mycobacterium bovis. Although the BCG vaccine has been one of the most widely used vaccines in the world for over 40 years, the genetic basis of BCG's attenuation has never been elucidated. We employed subtractive genomic hybridization to identify genetic differences between virulent M. bovis and M. tuberculosis and avirulent BCG. Three distinct genomic regions of difference (designated RD1 to RD3) were found to be deleted from BCG, and the precise junctions and DNA sequence of each deletion were determined. RD3, a 9.3-kb genomic segment present in virulent laboratory strains of M. bovis and M. tuberculosis, was absent from BCG and 84% of virulent clinical isolates. RD2, a 10.7-kb DNA segment containing a novel repetitive element and the previously identified mpt-64 gene, was conserved in all virulent laboratory and clinical tubercle bacilli tested and was deleted only from substrains derived from the original BCG Pasteur strain after 1925. Thus, the RD2 deletion occurred after the original derivation of BCG. RD1, a 9.5-kb DNA segment found to be deleted from all BCG substrains, was conserved in all virulent laboratory and clinical isolates of M. bovis and M. tuberculosis tested. The reintroduction of RD1 into BCG repressed the expression of at least 10 proteins and resulted in a protein expression profile almost identical to that of virulent M. bovis and M. tuberculosis, as determined by two-dimensional gel electrophoresis. These data indicate a role for RD1 in the regulation of multiple genetic loci, suggesting that the loss of virulence by BCG is due to a regulatory mutation. These findings may be applicable to the rational design of a new attenuated tuberculosis vaccine and the development of new diagnostic tests to distinguish BCG vaccination from tuberculosis infection.     

乙型肝炎疫苗-卡介苗联合疫苗动物安全性试验研究

为评价乙型肝炎疫苗-卡介苗联合疫苗的安全性,分别给豚鼠皮下注射、小鼠皮内注射乙型肝炎疫苗-卡介苗联合疫苗或卡介苗,豚鼠每2周称体重一次,观察6周,解剖检查其病理变化;小鼠也进行病理检查。结果乙型肝炎疫苗-卡介苗联合疫苗接种组和卡介苗接种组的豚鼠体重均增加,疫苗注射局部及各脏器病理改变相似;小鼠接种局部皮肤病理改变也未见差异。结论为乙肝表面抗原(HBsAg)没有促使卡介苗毒力增强,乙型肝炎疫苗-卡介苗联合疫苗接种实验鼠是安全的。     

The influence of adjuvant on induction of protective immunity by a non-living vaccine against schistosomiasis

Mice were protected against subsequent infection with Schistosoma mansoni by intradermal or s.c. vaccination with killed schistosomula or soluble parasite extracts and bacillus Calmette-Guérin (BCG). Treatment with i.p. immunization was somewhat less effective, whereas i.m. vaccination failed to elicit protective immunity. The level of resistance induced by intradermal immunization was influenced by the strain of BCG used, and isolated BCG cell walls did not reliably substitute for whole BCG organisms as adjuvant. Bordetella pertussis vaccine and saponin were also able to function as adjuvants for protective immunity in this model, whereas other immunopotentiators including Corynebacterium parvum and aluminum hydroxide were ineffective. No correlation between resistance to challenge infection and antibody levels was detected. Animals immunized intradermally using either protective or non-protective adjuvants all showed minimal humoral reactivity against schistosomulum surface Ag but strong IgG response to soluble parasite components including paramyosin, which is the major serologically recognized Ag in mice vaccinated intradermally with schistosome Ag plus BCG and is protective in this model. In contrast, a strong correlation was observed between resistance and Ag-specific cell-mediated reactivity, including IFN production by T lymphocytes in vitro and macrophage activation in vivo. These results further substantiate the hypothesis that protection in this model is based on cell-mediated immune effector mechanisms. Moreover, they may be of general relevance in the design of vaccination protocols using other Ag or against other infectious agents.     

流行性乙型脑炎病毒在Vero细胞上传代适应的研究

通过乙脑病毒Ｐ＿３株以不同方式在鼠脑和Ｖｃｒｏ细胞间传代适应的研究,培育出适于工业化大生产制备乙脑疫苗的生产毒种。其毒力可达７．０±０．５ｌｇＬＤ５０／０．０４ｍｌ,空斑滴度为７．５±０．５ＰＦＵ／ｍｌ,免疫原性ＩＤ５０值为０．００００１６－０．００００２３ｍｌ;在含有适量人白蛋白的１９９营养液内,该毒种于－３０℃至少可稳定一年;与鼠脑组织毒种相比,传代细胞毒种的毒力、免疫原性及稳定性均与其相当。然而,后者不含脑组织,至少降低了一种过敏的危险。另外,细胞毒种的制备无需手工解剖鼠脑,易于控制外源因子污染,易于标准化。对于大规模生产疫苗、提高疫苗产量和质量,传代细胞毒种比鼠脑组织悬液毒种具有明显的优点。     

Synergistic effect of bacillus calmette guerin and a tuberculosis subunit vaccine in cationic liposomes: increased immunogenicity and protection

In the present work, we evaluated a new TB vaccine approach based on a combination of the Mycobacterium bovis bacillus Calmette-Guérin (BCG) vaccine and a subunit vaccine consisting of the proteins Ag85B and ESAT-6. We demonstrate that in addition to its vaccine efficacy BCG is an immune modulator that can potentiate a Th1 immune response better than the well-known adjuvant mono phosphoryl lipid A, leading to enhanced recognition of the subunit vaccine Ag85B-ESAT-6. Importantly, adding a vehicle to the vaccine, such as the cationic liposome dimethyl dioctadecyl ammonium bromide (DDA), significantly increased the potentiating effect of BCG. This synergistic effect between BCG and Ag85B-ESAT-6/liposome required drainage to the same lymph node of all vaccine components but did not require direct mixing of the components and was therefore also observed when BCG and Ag85B-ESAT-6/liposome were given as separate injections at sites draining to the same lymph node. The resulting optimized vaccine protocol consisting of BCG and subunit in liposomes (injected side by side) followed by boosting with the subunit in conventional adjuvant resulted in an impressive increase in the protective efficacy of up to 7-fold compared with BCG alone and 3-fold compared with unaugmented BCG boosted by the subunit vaccine. Thus, these studies suggest an immunization strategy where a novel TB subunit vaccine is administered as part of the child vaccination program together with BCG in neonates and followed by subunit boosting.     

Recombinant BCG vaccine candidates

Given the variable protective efficacy provided by Mycobacterium bovis BCG (Bacillus Calmette-Guérin), there is a concerted effort worldwide to develop better vaccines that could be used to reduce the burden of tuberculosis. Recombinant BCG (rBCG) are vaccine candidates that offer some potential in this area. In this paper, we will discuss the molecular methods used to generate rBCG, and the results obtained with some of these new vaccines as compared with the conventional BCG vaccine in diverse animal models. Tuberculosis vaccine candidates based on rBCG are promising candidates, and some of them are now being tested in clinical trials.     

Beyond BCG: the potential for a more effective TB vaccine.

The 'Bacille Calmette-Guerin' (BCG) vaccine has been used throughout most parts of the world for the majority of the century. It is safe to use and cheap to produce, but there have been increasing doubts about its effectiveness. These doubts could not come at a worse time, as tuberculosis (TB) rates continue to rise, compounded by the AIDS epidemic, and outbreaks of tuberculosis caused by multidrug-resistant strains are more common even in advanced countries. As a result, there is now a concerted research effort to produce new TB vaccine candidates. These include DNA vaccines, recombinant and auxotrophic vaccines and subunit vaccines, all of which hold promise. The real difficulty will probably arise at the clinical trial level, when a decision must be made either to replace BCG or to boost existing BCG-induced immunity using these new-generation vaccines.     

Improve protective efficacy of a TB DNA-HSP65 vaccine by BCG priming

Vaccines are considered by many to be one of the most successful medical interventions against infectious diseases. But many significant obstacles remain, such as optimizing DNA vaccines for use in humans or large animals. The amount of doses, route and easiness of administration are also important points to consider in the design of new DNA vaccines. Heterologous prime-boost regimens probably represent the best hope for an improved DNA vaccine strategy. In this study, we have shown that heterologous prime-boost vaccination against tuberculosis (TB) using intranasal BCG priming/DNA-HSP65 boosting (BCGin/DNA) provided significantly greater protection than that afforded by a single subcutaneous or intranasal dose of BCG. In addition, BCGin/DNA immunization was also more efficient in controlling bacterial loads than were the other prime-boost schedules evaluated or three doses of DNA-HSP65 as a naked DNA. The single dose of DNA-HSP65 booster enhanced the immunogenicity of a single subcutaneous BCG vaccination, as evidenced by the significantly higher serum levels of anti-Hsp65 IgG2a Th1-induced antibodies, as well as by the significantly greater production of IFN-γ by antigen-specific spleen cells. The BCG prime/DNA-HSP65 booster was also associated with better preservation of lung parenchyma. The improvement of the protective effect of BCG vaccine mediated by a DNA-HSP65 booster suggests that our strategy may hold promise as a safe and effective vaccine against TB.     

不同年份生产的乙型脑炎减毒活疫苗SA14-14-2基因稳定性研究

为了研究不同年份生产的乙型脑炎减毒活疫苗病毒E蛋白基因稳定性,从分子水平控制乙型脑炎减毒活疫苗质量,确保疫苗安全性,本研究分析了不同年份生产的乙脑活疫苗病毒E蛋白基因核苷酸序列及编码的氨基酸序列,并与该疫苗原始种子、主种子、工作种子、乙脑病毒强、弱毒株进行比较。结果显示不同年份生产的乙脑活疫苗病毒E蛋白基因核苷酸序列与其原始种子、主种子、工作种子和基因库中登录的乙脑病毒弱毒株SA14-14-2的相应序列完全一致,与乙脑病毒强毒株SA14的E蛋白氨基酸序列比较有9个位点氨基酸发生了改变。不同年份生产的乙脑活疫苗病毒E蛋白基因稳定性表明该疫苗质量稳定、安全。