水痘一带状疱疹病毒研究进展

水痘－带状疱疹病毒（ＶＺＶ）是致人类疾病的重要疱疹病毒之一。为预防水痘与带状疱疹,日本研制成功水痘减毒活疫苗,并出口到世界一些国家。本文就ＶＺＶ的分子生物学特性、病毒的致病机制与临床特征、病毒感染的体液免疫与细胞免疫,水痘疫苗株病毒与疫苗等的研究情况作一简要综述。     

水痘疫苗:概论

<正>一、水痘疫苗发展的历史 真正的水痘疫苗的研制,可以说是从最近才开始的。但是,从很早以前,就进行了将水痘及带状疱疹患者的水疱液接种给健康儿童的尝试。1878年维也纳的Steinr曾记述将水痘患者的水疱液接种于10名儿童,经过8日的潜伏期后,有8名儿童发病。(4名发热并有水疱,4名仅有水痘)。1925年维     

水痘减毒活疫苗的研究进展

水痘是由水痘-带状疱疹病毒( VZV) 引起的一种高传染性疾病。接种疫苗是预防和控制VZV 流行的最有效手段。美国从1995 年开始实施儿童接种水痘疫苗的政策, 显著降低了水痘相关疾病的发病率和病死率。近年来, 水痘疫苗在我国应用越来越广泛。本文就水痘减毒活疫苗Oka 株的研发, 疫苗的有效性、安全性, 病毒减毒的分子生物学特征和免疫策略等方面进行综述, 以期能更全面地认识水痘减毒疫苗在预防和控制VZV 传播方面所起的作用。     

北京株水痘疫苗生产工艺的建立

目的:建立北京株水痘疫苗生产工艺,采用此生产工艺生产水痘减毒活疫苗。方法:采用细胞工厂培养2BS细胞,感染北京株水痘-带状疱疹病毒工作种子批,同时感染Oka株水痘-带状疱疹病毒工作种子批作对照,经洗涤、离心、收获、原液合并、冻干制备水痘减毒活疫苗,并进行各项检定。结果:对照两种不同毒株生产的水痘减毒活疫苗无明显差异,且各项检测指标均符合要求。结论:根据结果显示,可使用此毒株生产工艺大规模生产北京株水痘疫苗,与Oka株生产水痘疫苗无差异。如果用此毒株生产水痘疫苗供应市场,将会打破Oka株水痘疫苗国内市场的垄断。     

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。     

建立膜抗原荧光抗体试验评价北京株冻干水痘疫苗免疫效果

为了建立用于水痘疫苗接种后血清中特异性抗体检测的膜抗原荧光抗体(FAMA)法,并对接种水痘疫苗后儿童血清中水痘特异性抗体进行检测,评价北京株水痘疫苗的免疫效果。以水痘带状疱疹病毒(VZV)感染细胞作为抗原制备成固定抗原玻片,以异硫氰酸荧光素(FITC)标记的羊抗人IgG作为二抗建立FAMA法,并对该法的敏感性、特异性进行验证。运用此法对不同剂量北京株水痘疫苗接种后儿童血清中特异性抗体进行检测,分析儿童血清中水痘特异性抗体水平以及免后抗体阳转率,并与Oka株水痘疫苗进行比较。结果显示,FAMA法敏感性可达0.0196IU/ml,特异性好。应用此法检测300名观察者免前免后双份血清样本中抗VZVIgG,易感者中北京株水痘疫苗原苗(39810PFU/0.5ml)、2000PFU/0.5ml、500PFU/0.5ml接种组儿童血清免后抗体阳转率分别为100%、98.77%、85.42%,抗体几何平均滴度(GMT)分别为36.4、34.3、18.6,原苗与2000PFU间的抗体阳转率和GMT均无显著性差异(P>0.05),但原苗与500PFU、2000PFU与500PFU间的抗体阳转率和GMT均有显著性差异(P<0.05)。对照国产、进口Oka株水痘疫苗接种后抗体阳转率分别为95.35%、96.97%,抗体GMT分别为13.3、16.0,不同剂量北京株疫苗抗体阳转率与国产、进口Oka株疫苗相比,差别无显著性(P>0.05),但北京株疫苗原?     

水痘疫苗原液生产工艺改进

目的: 对现有水痘减毒活疫苗原液生产工艺进行改进,提高水痘疫苗原液产量及疫苗质量。方法: 2BS细胞传代至方瓶37代细胞,感染Oka株水痘-带状疱疹病毒工作种子批,35℃培养24h换病毒培养液(II)继续置35℃培养24h,取出使用Earle’s液洗涤方瓶细胞表面,当细胞病变达70%以上时,按120-360ml/瓶进行收获,置-65℃以下保存。经检定合格后进行合并、冻干制备水痘减毒活疫苗。结果: 使用此方法进行生产的水痘疫苗比较原工艺生产的水痘疫苗原液收获量大幅提升,并且疫苗的牛血清残留量与抗生素残留量则大幅下降,且各项检定指标全部合格。结论: 使用此方法生产水痘疫苗产量及质量比较原工艺有大幅度提升。     

7例水痘患者水痘带状疱疹病毒的分离与鉴定分析

目的对7例临床水痘患者的疱疹液样本,进行水痘带状疱疹病毒(varicella-herpes zoster virus,VZV)的分离及鉴定分析。方法对7例临床水痘患者的疱疹液,用2BS细胞进行病毒分离及病毒滴度检测;用特异性引物分别对病毒分离株及疫苗株(Oka株)的ORF68、ORF54、ORF38进行聚合酶链反应(Polymerase Chain Reaction,PCR)扩增及测序,用DNAMAN软件对病毒分离株的ORF68序列与Dumas株序列进行比对鉴定,并对病毒分离株和Oka株的ORF54、ORF38进行限制性片段长度多态性(restriction fragment length polymorphism,RFLP)分析。结果从7例临床水痘患者的疱疹液样本中,分离到4株VZV病毒株;病毒分离株的细胞病变(cytopathic effect,CPE)及病毒滴度随传代次数的增加而增强;4株病毒分离株的ORF68序列与Dumas株完全一致;ORF54、ORF38的RFLP结果显示,4株病毒分离株均为BglⅠ+PstⅠ+型,Oka株为BglⅠ+PstⅠ-型。结论成功分离的4株病毒分离株均为VZV野生毒株。     

水痘疫苗在学校暴发疫情中保护效果的回顾性队列研究

目的了解水痘疫苗在学校等集体单位水痘暴发疫情中的保护效果。方法选择佛山市2012年水痘暴发疫情的学校,按年龄分层,以接种水痘疫苗作为暴露因素,采用回顾性队列研究方法,评价水痘疫苗的保护效果。结果共有143名学生纳入研究对象,水痘疫苗的保护率为69.18%。按年龄分层分析发现,6～7岁组水痘疫苗保护率为86.12%,而9～11岁组水痘疫苗未显示保护作用。结论水痘疫苗对学校等集体单位水痘暴发疫情的控制具有良好的效果。但由于疫苗免疫机体后所产生的抗体衰减,小学高年级学生应适时加强接种一剂次水痘疫苗。     

水痘-带状疱疹病毒疫苗的评价与研究进展

水痘-带状疱疹病毒(VZV)属疱疹病毒α亚科,即人类疱疹病毒3型,为双链DNA病毒。原发感染可引起具有高度传染性的全球流行性疾病——水痘;潜伏病毒的再激活感染可引发典型的疼痛性皮肤病——带状疱疹及不典型的内脏器官感染。日本和美国分别自1987年和1995年开始实行给全体儿童预防接种水痘减毒活疫苗(vOka)后,两国儿童的水痘发病率和病死率显著降低。但VZV疫苗的不良反应,包括二次传播和突破感染等时有发生,因此有必要研发更为有效、安全的新型疫苗。本文就VZV相关疫苗的有效性、安全性及其新型疫苗的研究进展进行综述。     

Varicella Vaccination Alters the Chronological Trends of Herpes Zoster and Varicella

Background

Population studies on trends of varicella and herpes zoster (HZ) associated with varicella zoster vaccination and climate is limited.

Methods

This study used insurance claims data to investigate the chronological changes in incident varicella and HZ associated with varicella zoster vaccination. Poisson regression was used to estimate the occurrence of varicella associated with the occurrence of HZ and vice versa by year, season, sex, temperature, and sunny hours.

Results

The varicella incidence declined from 7.14 to 0.76 per 1,000 person-years in 2000–2009, whereas the HZ incidence increased from 4.04 to 6.24 per 1,000 person-years. Females tended to have a higher risk than men for HZ (p<0.0001) but not varicella. The monthly mean varicella incidence was the lowest in September (160 cases) and the highest in January (425 cases), while the mean HZ incidence was lower in February (370 cases) and higher in August (470 cases). HZ was negatively associated with the incidence of varicella before and after the varicella zoster vaccination (p<0.001), increased 1.6% within one week post-vaccination. The effect of temperature on HZ was attenuated by 18.5% (p<0.0001) in association with vaccination. The varicella risk was positively associated with sun exposure hours, but negatively associated with temperature only before vaccination.

Conclusions

The varicella vaccination is effective in varicella prevention, but the incidence of HZ increases after vaccination. HZ has a stronger association with temperature and UV than with seasonality while varicella risk associated with temperature and UV is diminished.     

Prevention of varicella in urgent cases by passive transfer of vaccine-induced immunity

For the purpose of preventing spread of infection to high risk children whose immunities were severely impaired by intensive chemotherapy or for some other reason, when cases of varicella occurred in a children's ward or in a family, healthy adults (mothers and a doctor) were immediately given live varicella vaccine, blood was collected from these adults 5 to 7 days after vaccination and the whole blood or plasma including the buffy coat was transferred in the high risk children. Subsequently the children showed little or no clinical reaction, and follow-up studies by the neutralizing test and skin test with varicella antigen indicated that their inapparent or subclinical varicella infection occurred in them and that their immunity to varicella was lasting. Skin tests with varicella antigen showed that booster reaction occurred in adults with a previous history of varicella as early as 5 to 7 days after vaccination. The cellular immunity thus induced in the donors may have played a role in preventing a clinical reaction in the high risk children. Thus passive transfer of vaccine-induced immunity seems a convenient and effective method for preventing infection in subjects whose immune capacities are severely impaired.     

Simian varicella virus antibody response in experimental infection of African green monkeys

Abstract: The humoral immune response to simian varicella virus (SVV) was investigated following primary and secondary experimental infection of African green monkeys. Neutralization and immunoprecipitation assays were used to determine antibody titers to SVV throughout the course of infection. The immune response to specific viral polypeptides was analyzed by immunoprecipitation analysis. The results demonstrate that the simian varicella model offers a useful approach to investigate immune mechanisms in human varicella zoster virus (VZV) infections.     

Comparison of 4 serological tests--complement fixation, neutralization, fluorescent antibody to membrane antigen and immune adherence hemagglutination--for assay of antibody to varicella-zoster (V-Z) virus.

Four tests for antibody to varicella-zoster (V-Z) virus were compared; these were tests of complement fixation (CF), neutralization (NT), fluorescent antibody to membrane antigen (FAMA) and immune adherence hemagglutination (IAHA). Fifty-two sera from patients with varicella and zoster and from recipients of live varicella vaccine were examined by the 4 tests. The CF test was least sensitive, but the antibody titers by the NT, FAMA and IAHA tests were roughly comparable. The IAHA test was the simplest and fastest to perform, and appeared suitable for routine serological assay to V-Z virus. The correlation between the IAHA antibody titer and susceptibility of individuals to clinical varicella was investigated retrospectively using sera obtained during 2 outbreaks of varicella in an institution for children, where all the unvaccinated children had developed varicella symptoms. Most of the 25 pre-exposure sera from unvaccinated children examined by the IAHA test had tiers of less than 1:2. In contrast, all the 23 sera from vaccinated children who did not develop varicella had detectable antibody titers of 1:2 to 1:64. These results indicate that the IAHA titer reflects the susceptibility or resistance of individuals to clinical varicella.     

Antibody responses to early antigens of varicella-zoster virus (VZV) during varicella and zoster

The antibody responses to membrane and early antigens and thymidine kinase of varicella-zoster virus (VZV) were studied in sera during both varicella and zoster by a test with fluorescent antibody to membrane antigen (FAMA), staining the biochemically transformed cells by the immunofluorescent technique and neutralization of virus-specific thymidine kinase activity, respectively. Similar increases in FAMA antibody titers were demonstrated in sera from patients with varicella and zoster. IgM was detected in both groups, but appeared earlier during varicella than during zoster. Furthermore, the antibody titers to early antigens and virus-specific thymidine kinase were higher in patients with zoster than in those with varicella. These data suggest that different types of antibody responses occur during varicella and zoster.     

A five-year immunological follow-up study of the institutionalized handicapped children vaccinated with live varicella vaccine or infected with natural varicella

Twenty-two institutionalized handicapped children who were susceptible to varicella were vaccinated with live varicella vaccine of the Oka strain and their immune status was followed for 5 years under conditions without exposure to natural varicella. Simultaneously, 7 children infected with natural varicella were followed. Of the 22 vaccinees, 16 showed sero-positive conversion by the fluorescent antibody to membrane antigen (FAMA) test, the other 6 remaining seronegative during 5 years of observation period. All the 16 cases showing seroconversion had detectable antibody for 5 years after vaccination, and 14 of them gave a positive reaction in the varicella skin test. All the 7 cases after natural varicella gave positive reactions in both the FAMA and skin test. These results suggest that immunity conferred by the vaccination would persist long even in the absence of exposure to natural varicella, though further follow-up studies are needed.     

Application of a live attenuated varicella vaccine to hospitalized children and its protective effect on spread of varicella infection.

Twenty-three hospitalized children with no history of varicella or no detectable complement fixing (CF) antibody, were vaccinated with a live attenuated varicella vaccine (Oka strain) immediately after the occurrence of a case of varicella in a children's ward of hospital. These children suffered from the nephrotic syndrome, nephritis, purulent meningitis, hepatitis etc., and 12 of them were receiving steroid therapy. An antibody response was noticed in all the vaccinated children, with mild fever in 6 and a mild rash in 2 of 6. It was uncertain whether these reactions were due to vaccinatin or to naturally acquired infection modified by vaccination. No other clinical reactions or abnormalities of the blood or urine were detected. Thus the spread of varicella infection was prevented, with the exception of one severe case in an unvaccinated patient. In another trial, 16 children with renal diseases were also vaccinated. All the children showed an immune response with no clinical reactions and no abnormalities in blood and urine examinations. Thus live varicella vaccine (Oka strain) can be used safely and effectively for hospitalized children, and its effectiveness in preventing spread of varicella infection was confirmed.     

Clinical application of a live varicella vaccine (Oka strain) in a hospital

A total of 239 children, including 22 high-risk children and 55 non-high risk diseased children have been immunized with a live varicella vaccine (Oka strain) since June, 1978. No clinical reaction attributable to the vaccine has been observed. Of these children, 87 received emergency vaccination. Of 47 children receiving emergency vaccination because they had been in contact with varicella patients either in hospital, school or a playground, only 5 developed varicella and their symptoms were mild. Of 40 children receiving emergency vaccination because of exposure to varicella in their home, 10 developed mild varicella and 30 were protected. Clinical symptoms of varicella when seen seemed to be due to incomplete protection because the vaccine was given too late rather than to clinical reactions to the vaccine. During follow-up period of 6 to 66 months after vaccination, 8 children showed very mild rashes without fever as the result of exogenous varicella infection.