Factors Associated with Antibody Levels among Children Aged 15 to 59 Months Vaccinated against Hepatitis B during the Expanded Program on Immunization in Cameroon

Background: the hepatitis B virus infection remains a major public health problem worldwide. It can lead to a liver cirrhosis and/or hepatocellular carcinoma. The World Health Organisation (WHO) has recommended the implementation of generalised vaccination programs against hepatitis B. In Cameroon, this vaccine was introduced in the expanded program on immunization (EPI) in 2005, but few studies have assessed the immune response. Objective: the general objective of this study was to identify factors associated with antibody levels among children aged from 15 to 59 months vaccinated against hepatitis B during the EPI in Cameroon. Method: this was a cross-sectional study carried out from December 2021 to June 2022 in a paediatric centre of Yaoundé (Cameroon). We analysed the antibody level in children vaccinated against hepatitis B within the framework of the EPI. We enrolled children who had received a series of 3 intramuscular doses of hepatitis B vaccine at 6, 10 and 14 weeks after birth. Some children could receive a 4th booster dose between 12 months. The antibody level was assessed by measuring the anti-HBs in such children, aged 15 - 59 months. A good immunization was defined as a serum level of anti-HBs antibody level above 100 IU/mL;a poor immunization, for an anti-HBs antibody level between 10 and 100 IU/mL;and a non-immunization, for an anti-HBs antibody level < 10 IU/mL. Association between explored factors and poor or non-immunization was evaluated through the Chi square test. The significance threshold was defined at p < 0.05. Results: sixty subjects were included in the study with a slight female majority: 31 cases (52%). The average age was 38.5 ± 15.7 months (range 15 - 59 months). We found 32 (53%) cases of good immunization;21 (35%) of poor immunization;and 7 children (12%) with a non-immunization. The only factor associated with poor or non-immunization was the age between 37 - 59 months (p = 0.016). Conclusion: Anti HBs Antibody levels in children vaccinated against hepatitis B virus were globally satisfactory in our series. Results show an association between low antibody levels with older age (over 36 months), suggesting a circulating antibodies levels decrease over time, yet deemed protecting until 59 months.

Generation of high affinity human single-hain antibody against PreSl of hepatitis B virus from immune phage-display antibody library

BACKGROUND: A single-chain antibody ( ScFv) phage display library was created by cloning antigen-binding re- gions of VH (variable domain) and VL gene repertoires as fusion proteins with a minor coat protein of filamentous phage, from which high affinity completely humanized ScFv against PreS1 of hepatitis B virus could be screened and characterized. METHODS: A combinatorial library of phage-display hu- man ScFv genes, which were derived from peripheral blood lymphocytes immunized by peptide PreS1 in vitro, was constructed. The library contained 7 × 108 clones. RESULTS: After 3 rounds panning, a high affinity (K = 10-7-10-8 mol/L) ScFv specific to PreS1 was obtained. Sequence analysis showed that the VH belonged to the VH4 family and Vλ to Vλ4. CONCLUSIONS: The described ScFv may provide a more satisfactory therapy. This application further illustrates that the method of in vitro antigen stimulation is expeditious for the source of human immune antibody library.

High prevalence of hepatitis B-antibody loss and a case report of de novo hepatitis B virus infection in a child after living-donor liver transplantation

AIM To assess the seroprevalence of hepatitis B virus(HBV) immunity among previously vaccinated pediatric liver transplant recipients and present a case report of de novo hepatitis B infection after liver transplantation.METHODS This study focused on children with chronic liver diseases who received primary hepatitis B immunization and had a complete dataset of anti-HBs before and after liver transplantation between May 2001 and June 2017. Medical records were retrospectively reviewed for potential factors relating to HBV immunity loss. RESULTS In total, 50 children were recruited. The mean time from liver transplantation to anti-HBs testing was 2.53 ± 2.11 years. The mean anti-HBs levels before and after liver transplantation were 584.41 ± 415.45 and 58.56 ± 6.40 IU/L, respectively. The rate of nonimmunity(anti-HBs < 10 IU/L) in the participants was 46%(n = 26) at one year, 57%(n = 7) at two years and 82%(n = 17) at > three years following liver transplantation. The potential factors relating to HBV immunity loss after liver transplantation were identified as anti-HBs(P = 0.002), serum albumin(P = 0.04), total bilirubin(P = 0.001) and direct bilirubin(P = 0.003) before liver transplantation. A five-year-old boy with biliary cirrhosis received 4 doses of HBV vaccine with an anti-HBs titer of > 1000 IU/L and underwent liver transplantation; his anti-HBc-negative father was the donor. After liver transplantation, the boy had stenosis of the hepatic artery up to the inferior vena cava anastomosis and underwent venoplasty three times. He also received subcutaneous injections of enoxaparin for 5 mo and 20 transfusions of blood components. Three years and ten months after the liver transplantation, transaminitis was detected with positive tests for HBs Ag, HBe Ag, and anti-HBc(2169.61, 1706 and 8.45, respectively; cutoff value: < 1.00) and an HBV viral load of 33212320 IU/mL.CONCLUSION The present study showed that loss of hepatitis B immunity after liver transplantation is unexpectedly common. In our case report, despite high levels of antiHBs prior to transplantation, infection occurred at a time when, unfortunately, the child had lost immunity to hepatitis B after liver transplantation.

Insights into induction of the immune response by the hepatitis B vaccine

After more than four decades of hepatitis B virus(HBV)vaccine implementation,its safety and efficacy in preventing HBV infection have been proven and several milestones have been achieved.Most countries have included HBV immunization schedules in their health policies and progress has been made regarding universalization of the first HBV vaccine dose at birth.All of these actions have significantly contributed to reducing both the incidence of HBV infection and its related complications.However,there are still many drawbacks to overcome.The main concerns are the deficient coverage rate of the dose at birth and the large adult population that has not been reached timely by universal immunization.Additionally,the current most widely used second-generation vaccines do not induce protective immunity in 5%to 10%of the population,particularly in people over 40-years-old,obese(body mass index>25 kg/m2),heavy smokers,and patients undergoing dialysis or infection with human immunodeficiency virus.Recently developed and approved novel vaccine formulations using more potent adjuvants or multiple antigens have shown better performance,particularly in difficult settings.These advances re-launch the expectations of achieving the World Health Organization’s objective of completing hepatitis control by 2030.

Immunogenicity and reactogenicity of a recombinant hepatitis B vaccine in subjects over age of forty years and response of a booster dose among nonresponders

AIM:The study was initiated to evaluate the reactogenicity and immunogenicity of a recombinant hepatitis B vaccine in age group >40 years and to study the response of a single booster dose in primary non-responders to the hepatitis B vaccination. METHODS:A total of 102 volunteers without markers of hepatitis B infection (negative for HBsAg,anti-HBc antibody, HBeAg and anti-HBs antibody) received 20μg of recombinant HB vaccine intramuscularly at 0,1,and 6 months.Anti HBs titers were evaluated by a quantitative Elisa kit at 90 and 210 days.A booster dose of 20μg HB vaccine was given after 6 months of the 3^(rd) vaccine dose to the 15 non- responders and anti-HBs titers were measured after i month. RESULTS:Seroprotection (anti-HBs GMT^3 10 IU/L) was achieved in 85.3 % (87/102) volunteers.The mean GMT titers of the vaccine responders was 136.1 IU/L.Of the seroprotected individuals,there were 32.4% (33/102) hyporesponders (anti- HBs titers <10-99 mIU/ml) and 52.9% (54/102) were responders (anti-HBs titers >100 IU/L).All the non-responders (15/15) responded to a single dose of the booster dose of recombinant HB vaccine and their mean anti-HBs antibody titers were more than 100.5 mIU/ml after the booster dose. CONCLUSION:Recombinant hepatitis B vaccine offers good seroprotection in the age group >40 years and has a good safety profile.A single booster dose after 6 months in primary non-responders leads to good seroprotective anti-HBs antibody titers.However,larger population based studies are needed to evaluate the role of a booster dose in selected group of non-responders and whether such an approach will be cost effective.

Humoral and cellular immunogenecity of DNA vaccine based on hepatitis B core gene in rhesus monkeys

INTRODUCTIONHepatitis B virus (HBV) is the most commonetiologic agent for infectious liver diseases. It isestimated that there are more than 250 millionchronic HBV carriersin the world today and thereis a significant association among persistentinfection, liver cirrhosis and hepatocellularcarcinoma[1-3].

Vaccination Coverage and the Risk of Hepatitis B Virus Infection amongst Medical and Paramedical Students Practicing at the Bamenda Regional Hospital in Cameroon Sub-Saharan Africa

Introduction: The endemic nature of hepatitis B virus (HBV) in Sub-Saharan Africa is a significant public health problem that places health care providers (medical students inclusive) at increased risk of occupational exposure. However, vaccination against HBV is not systematic among medical students in Cameroon. Thus, we sought to evaluate awareness and HBV vaccine coverage amongst medical students in Cameroon. Aim: The present study was aimed at determining the proportion of Medical and Paramedical students on internship at the Bamenda Regional Hospital (BRH) who are vaccinated and immune to hepatitis B virus (HBV). Methods: This was a hospital-based cross sectional study carried out at the BRH in Cameroon. Questionnaires were administered to 120 participants who signed an informed consent form and venous blood samples collected in dry tubes for the HBV-5 PANEL test. Data were collected within a period of two weeks. HBV vaccine status was defined as complete (3 doses), partial (1 or 2 doses), and unvaccinated. Results: Of 120 participants (87 females and 33 males), 56 (46.7%) were vaccinated at least once against HBV;15 (12.5%) were partially vaccinated and 41 (34.2%) completely vaccinated. Out of the 56 vaccinated individuals, only 13 (23.2%) were confirmed immunized against HBV by testing positive for hepatitis B surface antibodies. Only 3 (5.4%) students had done post-vaccination serologic test to confirm their immunized status. There was high exposure to potentially infected body fluids like blood (97.5%) and urine (87.5%). There was equally poor practice of adequate preventive measures like regular hand washing and the proper use of personal protective equipment. A prevalence of 3.1% of HBV amongst the unvaccinated group was recorded. Conclusion: Only 1 in 3 medical students had completed the HBV vaccination series and only 26.8% of this cohort was confirmed immunized against HBV. This highlights the need for improved health policies aimed at increasing access and coverage of HBV immunization in high risk groups such as health workers.

Seroconversion of Hepatitis B Vaccine in Young Bangladeshi Children: A Tertiary Centre Experience

Background: Hepatitis B virus (HBV) infection is one of the most important global health problems and active immunization is the single most important and effective preventive measure against HBV infection. Several studied show that HBV carrier rate is between 2% - 7% in Bangladesh. Bangladesh introduced hepatitis B vaccination in children through Expanded Program on Immunization (EPI) in 2005 that includes 3 doses which starts from six weeks after birth. Currently booster vaccination is not recommended any more. However, many studies on different countries observed a declined level of HBs-antibody over a period of 3 - 6 years that may even reach to non-protective levels. Objective: To evaluate the status of seroconversion and seroprotection along with non-responders of EPI vaccinated children against HBV and to measure their antibody levels in different age groups. Methods: A cross sectional descriptive study was done in the department of Pediatric Gastroenterology, Hepatology & Nutrition, Dhaka Shishu (Children) Hospital, Dhaka, Bangladesh on 120 cases of EPI vaccinated children enrolled from January-December 2019 while attending the inpatient department without any liver problem. The development of Anti-HBs titre greater than or equal to 10 mIU/mL is considered as protective immunity and any titre less than 10 mIU/mL as non-protective following HBV vaccination. Results: Age of the children was 1 - 12 years with mean age of 5.6 ± 1.7 years and male: female ratio was 1.1:1. Among the children, 56 (46.6%) were from 1 - 5 years age, 36 (30.1%) children from 6 - 10 years age group and 27 (23.3%) children from 11 - 12 years age group. Out of 120 children, presence of Anti-HBs protective titre was in 63 (52.5%) children and non-protective level in 57 (47.5%) children. Among protective level, 34 (60.7%) children were in 1 - 5 years age group, 18 (50.0%) children in 6 - 10 years age group and 11 (39.3%) children in 11 - 12 years age group. Total 24 (20%) children were completely non-responder (antibody titre 0.00 mIU/mL). Out of 120 mother, 06 (5%) were HBV positive. Among them 05 (83.33%) children had Anti-HBs less than 10 mIU/mL. Conclusion: After primary vaccination, a good immune response was detected against hepatitis B virus but it goes below even up to non-protective level with the increase of age. Half of the studied children had non-protective titre after 5 years and one-fifth children totally non-responder after primary hepatitis B vaccination. A booster dose may be recommended after 5 years for optimum seroprotection.

孕晚期肌肉注射HBIG与新生儿及产后乳汁HBV-DNA含量相关性分析

目的通过对孕产妇各个时期注射高效价乙肝免疫球蛋白(HBIG)后血清及乳汁中HBV DNA含量的分析、比较,为乙肝携带者孕产妇的乙肝病毒的母婴阻断及产后母乳喂养方案提供实验依据。方法选取2012年6月至2014年6月在该院产科门诊进行产前检查HBsAg(+)的乙肝携带者孕妇140例,根据自愿、保密的原则,分为研究组和对照组,其中研究组75例于孕期28、32、36周进行肌注高效价HBIG 200U,对照组65例中的孕产妇由于各种原因在孕期未进行HBIG注射。分别于注射前、分娩前检测两组血清中HBV DNA含量、分娩后对新生儿血清及3~5d内乳汁进行HBV DNA含量检测,分析两组的差异及相关性。结果注射HBIG前研究组HBV DNA含量<500copies/mL、500^(-1)×10~6copies/mL、>1×10~6 copies/mL分别为:28例、17例、30例,产前分别为:35例、20例、20例;对照组产前2次检测为:19例、21例、25例及20例、17例、28例;在研究组与对照组中新生儿血清HBV DNA阳性分别为:1例(5.3%)及5例(7.7%);在两组乳汁中HBV DNA阳性分别为:3例(4%)和8例(12.3%)。结论乙肝携带者孕妇在孕晚期进行HBIG的注射可能影响其乙肝病毒的复制进而减少新生儿宫内感染的概率,同时降低其产后乳汁的HBV DNA的阳性率。

抗HBV与HCV免疫乳的实验免疫研究

确定重组HBV表面抗原和HCV核心抗原对奶牛的最适免疫剂量、免疫次数及间隔时间,观察牛奶中抗HBV与抗HCV的效价与消长规律。表达HBV表面抗原和HCV核心抗原的重组菌经IPTG诱导后,目的蛋白以包涵体形式存在。放大发酵工艺,菌体发酵密度达40g/L,目的蛋白表达量为26%～30%。将包涵体变性、复性后,测定蛋白含量,并用SDS-PAGE鉴定。采用不同的剂量和不同的抗原处理方法免疫奶山羊和奶牛,检测HBV抗体、HCV抗体、干扰素与白介素等细胞因子。免疫奶山羊羊奶中的HBV抗体效价最高为1∶80,HCV抗体效价最高为1∶20;6个月后,HBV抗体效价无明显下降,HCV抗体效价下降明显。对奶牛5个批次的免疫结果显示,免疫次数应多于3次,免疫剂量以每头牛300μg为宜,间隔时间以1个月为宜。免疫牛奶中HBV抗体的阳性率约为66.0%,抗体效价最高为1∶160;HCV抗体阳性率约为17.0%,维持时间较短;孕牛比旺奶牛产生抗体的效价高。免疫牛奶中检测到了干扰素和白介素等细胞免疫活性因子。

应用酶联免疫吸附试验检测不同类型乙型肝炎中激活补体类HBsAg循环免疫复合物

本文以抗人C_(?)的羊IgG为包被抗体,以HRP-HBs抗体为指示抗体,建立了可检测激活补体类HBsAg循环免疫复合物(HBsAg/C3-CIC)的C_3捕捉法酶联免疫吸附试验。检测了236例六种类型临床诊断为乙型肝炎的病人血清标本,其阳性率分别为:无症状携带者(ASC)12.9％(4/31),急性肝炎(AH)36.7％(22/60),慢性迁延性肝炎(CPH)33.3％(7/21),慢性活动性肝炎(CAH)59.6％(34/57),重型肝炎(SH)77.8％(14/18),肝炎后肝硬化(PLC)67.3％(33/49),阳性率与肝损严重程度明显相关(P<0.01)。认为HBs-Ag/C3-CIC可能在乙型肝炎病毒引起的慢性活动性肝炎、重型肝炎和肝炎后肝硬化的发病过程中起重要作用,并可作为乙型肝炎的诊断、临床分型和预后判断的指标之一。

抗幽门螺杆菌UreB蛋白免疫乳的制备

诱导UreB蛋白克隆菌株表达UreB蛋白,并制备成亚单位疫苗,免疫正常泌乳奶牛,测定乳清中特异性抗体效价以及牛乳常规成分、血清常规成分等健康指标.结果表明:UreB蛋白表达浓度为0.39mg/mL;乳清特异性抗体IgG和IgM效价显著高于对照组(P<0.05),IgA效价有所上升,但未达到显著水平(P>0.05);奶牛血清中各项生理生化指标没有显著变化(P>0.05),乳清中除非脂型固形物差异显著外(P<0.05),其余指标没有显著差异(P>0.05).说明幽门螺杆菌UreB亚单位疫苗可以有效提高牛奶中特异性抗体的浓度,并对奶牛健康及牛奶成分没有显著影响.

HBsAg阳性母亲其婴幼儿联合阻断后无/低应答状态及加强免疫效果

目的评价HBsAg阳性母亲其婴幼儿联合阻断后无应答或低应答状态,了解乙肝疫苗加强免疫的干预效果。方法249例HBsAg阳性母亲其婴幼儿出生后予以联合免疫阻断,跟踪并测定出生后7～11个月、12～23个月、24～35个月、≥36个月的HBsAb水平,对其中50例无应答或低应答儿进行乙肝疫苗加强免疫接种,1个月后复查HBsAb水平。结果HBsAg阳性母亲其婴幼儿出生7个月后无应答和低应答的发生率为23.29%(58/249);高应答儿出生12～23个月时无应答和低应答的发生率为37.50%(45/120);持续高应答儿出生24～35个月时无应答和低应答率的发生率为48.14%(13/27)。给予乙肝疫苗加强免疫接种后,幼儿的HBsAb水平增高(P<0.05),加强免疫成功率为94%。性别及加强免疫接种时的年龄不影响加强免疫的效果(P>0.05)。结论HBsAg阳性母亲其婴幼儿全程乙肝疫苗接种后存在无应答及低应答状态,给予乙肝疫苗加强免疫干预后多见高应答状态。

G145R rHBsAg抗原衰减对抗体亲和层析的影响

目的:探讨G145R rHBsAg抗原衰减对抗体亲和纯化的影响与意义。方法:采用抗野生重组HBs G6-McAb制备层析载体,对含rG145R HBsAg的2A8细胞上清做亲和层析。以SDS-PAGE、Western Blot及ELISA等对产物纯度、含量及回收率进行评价,并与同法纯化之野生HBsAg进行比较。结果:梯度洗脱层析显示G145R rHBsAg、自然表达野生HBsAg及其r-wHBsAg三者纯化产物的纯度分别为90.3%、95.2%及93.1%;回收率为43.3%、72.0%及66.4%,其亲和洗脱峰型前者较后两者略宽,主峰前部出现明显顿挫;pH线性梯度洗脱显示,G145R rHBsAg洗脱曲线主峰较前梯度洗脱进一步增宽,顿挫更为明显,并在主峰前出现一低平的蛋白峰。ELISA检测显示HBsAg活性贯穿主峰始终,SDS-PAGE与Weistern blot显示两法洗脱产物纯度(92.5%与89.3%)大致相似,分子大小与野生HBsAg相同。结论:洗脱峰加宽与顿挫作为G145RrHBsAg抗原性渐进性衰减的特征性表现,在同类生物材料实验性制备与产品考评中有一定参考价值。

银川市新生儿血清抗-HBs水平影响因素及母婴血清抗-HBs滴度关联性研究

目的了解影响新生儿血清抗-HBs水平的相关因素和母婴血清抗-HBs之间的关系。方法对120名单胎出生的新生儿及其母亲,分别采集脐带血和静脉血3m L进行抗-HBs定量检测,并对血清抗-HBs滴度进行卡方检验和秩相关分析。结果母亲血清抗-HBs阳性率为58.3%(70/120),新生儿阳性率为60%(72/120),母婴均阳性的67对。新生儿血清抗-HBs水平汉族与回族间(χ~2=0.785,P>0.05)、城乡新生儿间(χ~2=3.261,P>0.05)、不同性别(χ~2=0.731,P>0.05)、不同分娩方式(χ~2=1.806,P>0.05)、不同胎次(χ~2=5.045,P>0.05),差异均无统计学意义。三组不同胎龄的新生儿血清抗-HBs水平差异有统计学意义(χ~2=15.275,P<0.05),随着胎龄的增高,新生儿血清抗-HBs浓度也将增高。对67对母婴血清抗-HBs滴度进行Spearman相关性分析发现,母婴血清抗-HBs滴度呈正相关(rs=0.928,P<0.01)。结论新生儿血清抗-HBs水平不受民族、城乡、性别、分娩方式和胎次的影响,但受胎龄的影响,对于长期没有接种乙肝疫苗的育龄妇女,建议怀孕前进行一针强化免疫。

HBV阳性母亲不同剂量免疫接种对婴儿的免疫效应

目的探讨不同剂量乙肝疫苗和乙肝免疫球蛋白对母亲为乙型肝炎（乙肝）病毒携带者婴儿的免疫效应。方法将423例生后均为乙肝表面抗原和乙肝e抗原定性检测阴性的婴儿，随机分为10μg乙肝疫苗（A）组、小荆量（〈10μg）乙肝疫苗（B）组、100U乙肝免疫球蛋白（C）组、200U乙肝免疫球蛋白（D）组、E组为C组加D组。除B组外，其他4组婴儿生后均按0、1、6个月方案各接种乙肝疫苗10μg。C组和D组婴儿生后第1天各用乙肝免疫球蛋白100U和200U肌肉注射，15～30天后按原量重复1次。观察婴儿生后1岁时乙肝保护性抗体——乙肝表面抗体定量检测、乙肝表面抗原和乙肝e抗原定性检测。结果423例婴儿生后1岁时乙肝表面抗原和乙肝e抗原定性检测均为阴性。在A组131例婴儿中，有84例乙肝表面抗体〉100mU／mL，占64．1％；在B组41例婴儿中，有14例乙肝表面抗体〉100mU／mL，占34．1％，两组比较，=11．446，P=0．001。C组136例婴儿中，有74例乙肝表面抗体〉100mU／mL，占54．4％，与A组比较r=2．604，P=0．107。D组115例婴儿中，有55例乙肝表面抗体〉100mU／mL，占47．8％，与A组比较，=6．617，P=0．010。E组251例婴儿中，有129例乙肝表面抗体〉100mU／mL，占51．4％，与A组比较X2=5．653，P=0．010。结论乙肝疫苗10μg注射3次的免疫效应显著优于小剂量乙肝疫苗注射3次的免疫效应。100U乙肝免疫球蛋白组1岁时乙肝表面抗体高值率低于10μg乙肝疫苗组，但经比较无显著性差异，200U乙肝免疫球蛋白组1岁时乙肝表面抗体高值率明显低于10μg乙肝疫苗组，经比较有显著性差异。说明乙肝免疫球蛋白剂量越大对乙肝疫苗产生抗体抑制越明显。

HBV preS2-S DNA免疫诱导小鼠体液免疫应答

目的:构建HBV表面抗原preS2 S 基因表达质粒,并探讨其在小鼠体内的表达及诱导体液免疫应答的能力。方法:采用PCR方法,以PBR322 HBV2.0(adr亚型)质粒DNA为模板获得HBV preS2 S 基因,并将其重组进入pcDNA3.0表达载体中,转染7721细胞系进行稳定表达;以此重组质粒免疫小鼠,ELISA方法检测免疫小鼠抗HBs抗体浓度。结果:构建了HBV preS2 S 基因的表达质粒pcDNAS2 S,该表达质粒可在7721 细胞中稳定高效表达;免疫接种小鼠2 周后抗HBs抗体浓度明显升高,接种后第4周布比卡因处理组小鼠抗HBs抗体的浓度达到峰值161.4 mIU/ml,布比卡因非处理组第5周抗HBs抗体的浓度可达133.7 mIU/ml。结论:所构建的pcDNAS2 S表达质粒能有效表达并诱导小鼠体液免疫应答。

抗HBcAg人源性单链抗体细胞内表达及其抗病毒复制的实验研究

应用人源性抗HBcAg单链抗体细胞内表达技术 ,探讨抗HBV复制基因治疗的应用价值。应用噬菌体展示和基因重组技术 ,从HBV感染的外周血淋巴细胞克隆了人源性抗HBcAg单链抗体 ,并重组至逆转录病毒载体。以人肝癌细胞smmc - 772 1和PLC/PRF/5为靶细胞进行基因共转染 ,分别测定实验组细胞上清中的HBsAg和HBeAg ,与对照组做比较 ,观察抗HBcAg单链抗体细胞内表达的抗病毒治疗作用。结果显示 ,在急性HBV感染的细胞株中 ,抑制病毒复制效率为 4 9%～ 6 1% ,在慢性病毒感染细胞 ,抑制率为 4 1%～ 5 4 %。实验结果表明 ,应用单链抗体细胞内表达技术 ,在抗病毒治疗研究中具有潜在的应用价值。应对HBV的 4个开放阅读框架编码产物进行全面的对比研究 ,以发现抑制效率高。

特异性免疫牛奶对HBV和HCV的预防感染作用研究

目的 观察正常人饮用免疫牛奶预防HBV和HCV感染的作用,同时观察正常人饮用免疫牛奶预防其他病原体感染的作用。 方法 选用符合条件的人员共164人,不分男女、年龄,随机分为2个组,分别食用免疫牛奶和普通牛奶3个月,检测饮用牛奶前后实验人群的血清HBsAg和抗HCV ,记录有无感冒及感冒次数等。 结果 免疫牛奶组与普通牛奶组相比,有预防HBV感染的作用,但对预防HCV感染无作用;该免疫牛奶对预防流感病毒感染也有一定作用。 结论 该免疫牛奶可以提高人体抗HBV和感冒病毒的能力。

HBV感染者对前S_1多肽抗体应答的初步探讨

本文采用Western Blot方法调查不同HBV感染者对前S_1多肽的抗体应答情况。结果发现:HBV感染者前S_1多肽抗体的总检出率为2.34％,隐性HBV感染自限组和现症乙肝病人组分别为17.24％和1.21％。表明抗前S_1多肽抗体主要存在于HBV感染自限人群血清中,机体对前S_1多肽有效的免疫应答对清除HBV感染,促进病情恢复和重症肝炎的发生超重要作用。