Advances in Zika virus vaccines and therapeutics:A systematic review

Zika virus(ZIKV)is the causative agent of a viral infection that causes neurological complications in newborns and adults worldwide.Its wide transmission route and alarming spread rates are of great concern to the scientific community.Numerous trials have been conducted to develop treatment options for ZIKV infection.This review highlights the latest developments in the fields of vaccinology and pharmaceuticals developments for ZIKV infection.A systematic and comprehensive approach was used to gather relevant and up-to-date data so that inferences could be made about the gaps in therapeutic development.The results indicate that several therapeutic interventions are being tested against ZIKV infection,such as DNA vaccines,subunit vaccines,live-attenuated vaccines,virus-vector-based vaccines,inactivated vaccines,virus-like particles,and mRNA-based vaccines.In addition,approved anti-ZIKV drugs that can reduce the global burden are discussed.Although many vaccine candidates for ZIKV are at different stages of development,none of them have received Food and Drug Authority approval for use up to now.The issue of side effects associated with these drugs in vulnerable newborns and pregnant women is a major obstacle in the therapeutic pathway.

Antibodies elicited by Newcastle disease virus-vectored H7N9 avian influenza vaccine are functional in activating the complement system

H7N9 subtype avian influenza virus poses a great challenge for poultry industry.Newcastle disease virus(NDV)-vectored H7N9 avian influenza vaccines(NDV_(vec)H7N9)are effective in disease control because they are protective and allow mass administration.Of note,these vaccines elicit undetectable H7N9-specific hemagglutination-inhibition(HI)but high IgG antibodies in chickens.However,the molecular basis and protective mechanism underlying this particular antibody immunity remain unclear.Herein,immunization with an NDV_(vec)H7N9 induced low anti-H7N9 HI and virus neutralization titers but high levels of hemagglutinin(HA)-binding IgG antibodies in chickens.Three residues(S150,G151 and S152)in HA of H7N9 virus were identified as the dominant epitopes recognized by the NDV_(vec)H7N9 immune serum.Passively transferred NDV_(vec)H7N9 immune serum conferred complete protection against H7N9 virus infection in chickens.The NDV_(vec)H7N9 immune serum can mediate a potent lysis of HA-expressing and H7N9 virus-infected cells and significantly suppress H7N9 virus infectivity.These activities of the serum were significantly impaired after heat-inactivation or treatment with complement inhibitor,suggesting the engagement of the complement system.Moreover,mutations in the 150-SGS-152 sites in HA resulted in significant reductions in cell lysis and virus neutralization mediated by the NDV_(vec)H7N9 immune serum,indicating the requirement of antibody-antigen binding for complement activity.Therefore,antibodies induced by the NDV_(vec)H7N9 can activate antibody-dependent complement-mediated lysis of H7N9 virus-infected cells and complement-mediated neutralization of H7N9 virus.Our findings unveiled a novel role of the complement in protection conferred by the NDV_(vec)H7N9,highlighting a potential benefit of engaging the complement system in H7N9 vaccine design.

56 Years of the Marburg Virus—A Review of Therapeutics

Background: The Marburg virus (MARV) is the causative agent of Marburg virus disease (MVD). This filovirus first appeared in 1967 and has since caused several outbreaks with case fatality rates between 23% and 90%. The earliest cases of MVD are thought to be caused by exposure to an infected animal, either a reservoir host (some bat species, e.g., Rousettus aegyptiacus) or a spill-over host, such as non-human primates. The virus is spread between people by direct contact with blood or other bodily fluids (including saliva, sweat, faeces, urine, tears, and breast milk) from infected individuals. Despite the high fatality rate, the Marburg virus has no vaccine or drug treatment. Recent outbreaks of the virus in 2023 in Tanzania and Equatorial Guinea have reignited the need to develop effective therapeutics, especially in the wake of the COVID-19 pandemic. Purpose: This review seeks to highlight the drug discovery efforts aimed at developing vaccines or possible treatments as potential therapeutics. Several existing antiviral agents are being probed, and vaccines are in pre-clinical and clinical stages. Natural products are also an important source of possible drugs or lead compounds and when coupled with computational techniques, these strategies offer possible therapeutics for the Marburg virus, especially in Africa, which has a high disease burden. Methods: Using the search engines Google Scholar and PubMed;keywords e.g. Marburg virus, Marburg treatments, Marburg virus drug discovery were utilized. Several results were yielded, and articles published in recent years were accepted into the final list.Results and Conclusion: This study shows there is a growing interest in therapeutics for the Marburg virus, especially with the recent outbreaks and pandemic preparedness. Initiatives that to support vaccine development and access like the MARVAC consort time are critical to fighting this public health threat.

Perception of Medical Students towards Hepatitis B Virus Infection and Hepatitis B Vaccination in a Private Tertiary Hospital in Jos North Local Government, Plateau State, Nigeria

Background: Prevention is one of the safe schemes against the high prevalence of viral Hepatitis. Negative perceptions or perceptions about the risks of hepatitis B among medical students and health care workers may influence the behavioral pattern and adoption of preventive measures against the virus and can affect the uptake of the Hepatitis B vaccine. This study assesses the perception of medical students towards Hepatitis B virus infection and Hepatitis B Vaccination in a Private Tertiary Hospital in Jos North Local Government, Plateau State, Nigeria. Methods: This was a descriptive cross-sectional study done in August 2021 among 236 clinical medical students using a multistage sampling technique. Data was collected using an interviewer-administered structured questionnaire and analysed using the IBM SPSS 28 (Statistical Package for the Social Sciences). Ethical approval was granted by Bingham University Teaching Hospital, Ethics Committee, Jos, Plateau State. Results: Two-thirds of respondents were of the opinion that they are at risk of contracting HBV. Half were of the opinion that the risk is very much while a third believed the risk is moderate. Among those who think they are not at risk of contracting HBV, the majority felt so because they are vaccinated while 10.3% believe that they are safe. 43.2% of respondents think that HBV Vaccine is very effective in preventing HBV infection while 39.8% think it is slightly effective, and 7.6% think it is not effective. Almost all respondents, 99.2% are of the opinion that HBV Vaccination is important for students while 0.8% think it is not important. The majority of the respondents at 95.8% were willing to be screened for HBV. The majority (85.6%) of respondents are willing to pay for HBV Vaccine as against 14.4% of respondents who are not willing to pay. Conclusion: Summarily, 21 (8.9%) of the students had a negative perception of Hepatitis B Vaccination, and 215 (91.1%) had a positive perception of Hepatitis B Vaccination. Perception-sustaining events like seminars, workshops, road shows, and campaigns should be organized among students and health workers.

Varicella zoster virus vaccines: potential complications and possible improvements

Varicella zoster virus(VZV) is the causative agent of varicella(chicken pox) and herpes zoster(shingles). After primary infection, the virus remains latent in sensory ganglia, and reactivates upon weakening of the cellular immune system due to various conditions, erupting from sensory neurons and infecting the corresponding skin tissue. The current varicella vaccine(v-Oka) is highly attenuated in the skin, yet retains its neurovirulence and may reactivate and damage sensory neurons. The reactivation is sometimes associated with postherpetic neuralgia(PHN), a severe pain along the affected sensory nerves that can linger for years, even after the herpetic rash resolves. In addition to the older population that develops a secondary infection resulting in herpes zoster, childhood breakthrough herpes zoster affects a small population of vaccinated children. There is a great need for a neuro-attenuated vaccine that would prevent not only the varicella manifestation, but, more importantly, any establishment of latency, and therefore herpes zoster. The development of a genetically-defined live-attenuated VZV vaccine that prevents neuronal and latent infection, in addition to primary varicella, is imperative for eventual eradication of VZV, and, if fully understood, has vast implications for many related herpesviruses and other viruses with similar pathogenic mechanisms.

Porcine reproductive and respiratory syndrome virus vaccines: Immunogenicity, efficacy and safety aspects

Porcine reproductive and respiratory syndrome virus(PRRSV) infection is the leading cause of economic casualty in swine industry worldwide. The virus can cause reproductive failure, respiratory disease, and growth retardation in the pigs. This review deals with current status of commercial PRRS vaccines presently used to control PRRS. The review focuses on the immunogenicity, protective efficacy and safety aspects of the vaccines. Commercial PRRS modified-live virus(MLV) vaccine elicits delayed humoral and cell-mediated immune responses following vaccination. The vaccine confers late but effective protection against genetically homologous PRRSV, and partial protection against genetically heterologous virus. The MLV vaccine is of concern for its safety as the vaccine virus can revert to virulence and cause diseases. PRRS killed virus(KV) vaccine, on the other hand, is safe but confers limited protection against either homologous or heterologous virus. The KV vaccine yet helps reduce disease severity when administered to the PRRSV-infected pigs. Although efforts have been made to improve the immunogenicity, ef-ficacy and safety of PRRS vaccines, a better vaccine is still needed in order to protect against PRRSV.

Cloning of M and NP Gene of H5N1 Avian Influenza Virus and Immune Efficacy of their DNA Vaccines

H5N1 鸟的流行性感冒病毒(A/chicken/Hubei/489/2004 ) 的 M 和 NP 基因被 RT-PCR 从病毒的 RNA 放大，并且分别地克隆向量进 pMD18-T。包含 M 基因(pHM6-m ) 或 NP 基因(pHM6-np ) 的表示 plasmid 然后被把 M 或 NP 基因插入到 pHM6 优核质表示向量构造；构造 plasmid 然后被定序。32 只 BALB/c 老鼠(6-week-old ) 在随机被划分成四个组。三组 BALB/c 老鼠被接种一次有 plasmid pHM6-m， plasmid pHM6-np 的 30 渭 g 或 plasmid pHM6-m (15 渭 g ) 和 pHM6-np (15 渭 g ) 的混合的任何一个 30 渭 g 的肌内的线路分别地。老鼠的一个另外的组作为控制与 100 渭 l PBS 被注射。二个星期以后，所有老鼠与相应 H5N1 鸟的流行性感冒病毒被质问，并且在下列 12 天内观察了。在 pHM6-m 组， pHM6-np 组和混合 plasmids 组的老鼠的幸存率分别地是 62.5% ， 25.0% 和 50.0% 。结果证明有效保护能被 pHM6-m 或 pHM6-np 提供，但是 pHM6-m 比 pHM6-np 提供了更好保护的效果。关键词 H5N1 流行性感冒病毒 - M 基因 - NP 基因 - 克隆 - DNA 疫苗的 CLC 数字 S852.65 基础条款：国家基本科学才能训练资助(NSFC J0630648 )

Immunogenicity of DNA and Recombinant Sendai Virus Vaccines Expressing the HIV-1 gag Gene

Combinations of DNA and recombinant-viral-vector based vaccines are promising AIDS vaccine methods because of their potential for inducing cellular immune responses. It was found that Gag-specific cytotoxic lymphocyte (CTL) responses were associated with lowering viremia in an untreated HIV-1 infected cohort. The main objectives of our studies were the construction of DNA and recombinant Sendai virus vector (rSeV) vaccines containing a gag gene from the prevalent Thailand subtype B strain in China and trying to use these vaccines for therapeutic and prophylactic vaccines. The candidate plasmid DNA vaccine pcDNA3.1(+)-gag and recombinant Sendai virus vaccine (rSeV-gag) were constructed separately. It was verified by Western blotting analysis that both DNA and rSeV-gag vaccines expressed the HIV-1 Gag protein correctly and efficiently. Balb/c mice were immunized with these two vaccines in different administration schemes. HIV-1 Gag-specific CTL responses and antibody levels were detected by intracellular cytokine staining assay and enzyme-linked immunosorbant assay (ELISA) respectively. Combined vaccines in a DNA prime/rSeV-gag boost vaccination regimen induced the strongest and most long-lasting Gag-specific CTL and antibody responses. It maintained relatively high levels even 9 weeks post immunization. This data indicated that the prime-boost regimen with DNA and rSeV-gag vaccines may offer promising HIV vaccine regimens.

Construction of Three Nucleic Acid Vaccines of Swine Hepatitis E Virus ORF2 Ger\e Continuous Fragment

In order to develop swine hepatitis E （HE） genetically engineering vaccines, specific primers of genes LB1, LB2, LB3 of swine hepatitis E virus were designed and used for amplification, DNA amplieons generated by PCR assays were directly cloned into T-A plasmid and expressed using pEASY-M1 expression vector. Three recombinant eukaryotic expression plasmids of pEASY-LB1, pEASY-LB2 and pEASY-LB3 were constructed. The eukaryotic expression plasmids of pEASY-LB1, pEASY-LB2, and pEASY-LB3 were transfected into 293T cells, and three target genes were detected by real-time fluorescent quantitative RT-PCR. The results confirmed that three eukaryotic expression plasmids were transfected into 293Teells and target protein was expressed. Analysis by SDS-PAGE electrophoresis and Western-blot indicated that three target proteins were expressed in 293T cells transfected with eukaryotic expression plasmids of pEASY-LB1, pEASY-LB2 and pEASY-LB3. Antigenicity studies indicated good HEV responses. Therefore, three recombinant DNAs of HEV ORF2 nucleic acid vaccine candidates were ob- tained, which might lay the foundation for further studies in the future.

In the era of rapid mRNA-based vaccines:Why is there no effective hepatitis C virus vaccine yet?

Hepatitis C virus(HCV)is responsible for no less than 71 million people chronically infected and is one of the most frequent indications for liver transplanta-tion worldwide.Despite direct-acting antiviral therapies fuel optimism in controlling HCV infections,there are several obstacles regarding treatment accessibility and reinfection continues to remain a possibility.Indeed,the majority of new HCV infections in developed countries occur in people who inject drugs and are more plausible to get reinfected.To achieve global epidemic control of this virus the development of an effective prophylactic or therapeutic vaccine becomes a must.The coronavirus disease 19(COVID-19)pandemic led to auspicious vaccine development against severe acute respiratory syndrome coronavirus-2(SARSCoV-2)virus,which has renewed interest on fighting HCV epidemic with vaccination.The aim of this review is to highlight the current situation of HCV vaccine candidates designed to prevent and/or to reduce HCV infectious cases and their complications.We will emphasize on some of the crossroads encountered during vaccine development against this insidious virus,together with some key aspects of HCV immunology which have,so far,ham-pered the progress in this area.The main focus will be on nucleic acid-based as well as recombinant viral vector-based vaccine candidates as the most novel vaccine approaches,some of which have been recently and successfully employed for SARS-CoV-2 vaccines.Finally,some ideas will be presented on which methods to explore for the design of live-attenuated vaccines against HCV.

Oral Administration Following Subcutaneous Administration of FCV Vaccines Enhances Vaccine Efficacy against Challenge of a Highly Virulent Vs Feline Calicivirus

Feline calicivirus (FCV) is a common cause of upper respiratory and oral disease in cats. Highly virulent systemic strains of FCV (vs FCV) have been described. These vs FCV isolates cause characteristic edema, cutaneous ulcers and other clinical signs typically associated with FCV infection. Vs FCV isolates also cause high mortality even in previously vaccinated cats. We reported previously that the FCV serum cross-neutralization profile of cat serum generated using the oralnasal route of administration is broader than with subcutaneous administration (SC), as measured with a 26-FCV viral panel (Rong et al., Virus Research 122:95-108, 2006). In this report, we tested the in vivo ef- ficacy of the FCV vaccine, in a 4-way (FCV-FHV-FPV-FCp) format, by using a highly virulent vs FCV- 33585 as the challenge virus. Vaccines were administered as 2-dose subcutaneouly (SC/SC), or subcutaneously followed by orally (SC/Oral). The mortality induced by vs FCV-33585 in unvaccinated control cats was 78% (7 out of 9 cats). The mortality decreased to 44% (4 out of 9 cats) with cats vaccinated with the 4-way vaccine given SC/SC. However, when this vaccine was given SC/Oral, the mortality decreased to 10% (1 out of 10 cats). The clinical scores, calculated based on frequency and severity of various clinical signs, correlated with mortality data. These results demonstrated that oral administration of FCV vaccines, as the second dose following the first dose of subcutaneious administration, ehances FCV efficacy against challenge of a highly virulent vs FCV. We propose that not only oral vaccination offers convenience and needle-free inoculation, it also enhances FCV vaccine efficacy.

Design of live-attenuated animal vaccines based on pseudorabies virus platform

Pseudorabies virus(PRV)is a double-stranded DNA virus with a genome approximating 150 kb in size.PRV contains many non-essential genes that can be replaced with genes encoding heterogenous antigens without affecting viral propagation.With the ability to induce cellular,humoral and mucosal immune responses in the host,PRV is considered to be an ideal and potential live vector for generation of animal vaccines.In this review,we summarize the advances in attenuated recombinant PRVs and design of PRV-based live vaccines as well as the challenge of vaccine application.

Uptake of Two Doses of HPV Vaccines in Nakuru County, Kenya: A Case of Rongai and Nakuru West Sub-Counties

Background: HPV vaccines were introduced globally as one of the most effective strategies to prevent cervical cancer. HPV vaccines were rolled out in Kenya in 2019 targeting girls aged 10 - 14 years, but the uptake has not been satisfactory. The Purpose of the Study: The aim of the study was to assess the level of HPV uptake among girls aged 10 - 14 years in Rongai and Nakuru West Sub-Counties in Nakuru County. Method: This was a cross-sectional study where data on HPV uptake was retrieved from all the public health facilities located in Rongai and Nakuru West Sub-Counties, Nakuru County, entered into Microsoft Excel then transferred to SPSS version 26 for analysis of HPV vaccine uptake since the year 2019 to June 2022. Data Analysis: Descriptive statistics were used where tables and graphs were generated to represent the percentages and trends of HPV vaccine uptake. Results: The average percentage of HPV uptake in Nakuru West Sub-County since the rollout of vaccination was 17% while that of Rongai Sub-County was 15%. In 2019, HPV 1 uptake was generally low for both Sub-Counties, the results show no HPV 2 vaccines were administered during that year. In 2020, Nakuru West reported an increase in HPV 1 uptake, while Rongai reported a drop in HPV 1 uptake. Both Sub-Counties reported an increase in HPV 2 in 2020 as compared to the previous year. The highest HPV 1 & 2 uptakes were reported in 2021 in both Sub-Counties. The uptake of both HPV 1 & 2 kept increasing subsequently. Conclusion: The overall uptake of HPV vaccines for Doses 1 and 2, in both Rongai and Nakuru West Sub-Counties, is low. However, there has been a consistent increase in uptake of the two doses in the two Sub-Counties since 2019. Therefore, raising public awareness of the importance of HPV vaccination could improve uptake.

非洲猪瘟基因Ⅰ型/Ⅱ型重组病毒研究现状及思考

基因重组在非洲猪瘟病毒(ASFV)基因组间广泛存在,它是造成ASFV遗传多样性的原因之一。ASFV基因Ⅱ型毒株2018年传入我国,2021年国内又报道发现基因Ⅰ型毒株和基因Ⅰ型/Ⅱ型重组病毒。我国分离的ASFV基因Ⅰ型/Ⅱ型重组毒嵌合了两个基因型序列并部分整合了二者的生物学特性,毒力与基因Ⅱ型强毒株相当,某些致病指标甚至更高;基因Ⅱ型减毒活疫苗株不能对该重组毒株产生有效保护。该重组毒株在国内的流行演变可能会显著影响ASFV的进化方向,并对ASFV疫苗研究带来新的挑战。本文通过对国内ASFV基因Ⅰ型/Ⅱ型重组病毒进行综述,就相关研究进展进行总结归纳,以期为我国ASF防控提供参考。

尼帕病毒病疫苗研究进展

尼帕病毒病是一种人兽共患病,1998年在马来西亚首次出现。引起该病的病原为尼帕病毒,它是一种单负股RNA病毒,可感染猪、马、犬、猫等多种动物,对人的致死率可达75%以上。目前,尚无有效疫苗上市。该病毒的表面糖蛋白是目前疫苗研究的主要靶标。以此为靶标,已有多种候选疫苗在不同动物模型中表现出良好的免疫效果,其中亚单位疫苗、重组活载体疫苗和mRNA疫苗是当前研究热点,已有3种相关人用候选疫苗进入临床试验。目前尼帕病毒病兽用疫苗研究进展缓慢,而兽用疫苗的使用可以有效预防病毒的跨种传播,符合“同一健康”理念,因此应加大兽用疫苗的研发力度。本文对尼帕病毒病不同类型疫苗相关研究进展进行了综述,并探讨了疫苗研究中的问题,以期为尼帕病毒病疫苗研究提供参考。

广西H9N2亚型禽流感病毒疫苗候选株的筛选

【目的】筛选出免疫原性更优的H9N2亚型禽流感病毒(AIV)疫苗候选株用于新型疫苗研发,为加强对H9N2亚型AIV的防控提供技术支持。【方法】以2000—2020年广西地区分离获得的36株H9N2亚型AIV分离株为试验材料,依据HA基因遗传进化分析选择12株不同年份、不同地域及不同宿主来源的H9N2亚型AIV代表株,与目前使用的商品化H9亚型AIV疫苗株(SS株)进行交叉血凝抑制试验(HI)及抗原性分析,根据抗原分析结果选择其中具有不同抗原差异的代表株制备油乳剂灭活疫苗,并分别与商品化H9亚型AIV疫苗(SS株)进行交叉免疫保护试验。【结果】在36株H9N2亚型AIV广西分离株中有31株属于Y280-Like(9.4.1),其中26株属于分支I、5株属于分支II,另外5株属于G1-Like(h9.4.1),与我国常用疫苗株分属于不同进化分支。12株H9N2亚型AIV广西代表性分离株灭活后的HA效价≥7 log2,病毒灭活效果良好,可用于制备油乳剂灭活疫苗,且制备的油乳剂灭活疫苗稳定性和安全性良好。根据交互HI抗体滴度计算出各毒株间的抗原相关值(R),结果发现A/chicken/Guangxi/C227/2015(H9N2)株(简称C227株)与其他毒株的抗原性无明显差异,对应的R在0.72~0.93间波动;疫苗交叉保护试验结果也表明,C227株制备的油乳剂灭活疫苗对不同毒株的免疫保护率均高于80%,且免疫保护效果优于A/chicken/Guangxi/CX/2013(H9N2)株(简称CX13株),说明C227株更适合作为H9N2亚型AIV灭活疫苗的候选株。【结论】基于抗原性分析和免疫原性测定筛选出的A/chicken/Guangxi/C227/2015(H9N2)株对广西地区绝大部分H9N2亚型AIV流行株的免疫保护效果良好,可作为疫苗候选株用于研制新型H9N2亚型AIV疫苗。

新型PCV2衣壳融合蛋白在HEK293F细胞瞬时表达研究

猪圆环病毒2型(Porcine Circovirus type 2,PCV2)衣壳(Capsid)蛋白是制备抗猪圆环2型病毒亚单位疫苗的有效免疫抗原,能在大肠杆菌及杆状病毒/昆虫细胞表达系统中获得表达,然而在哺乳细胞中的表达研究仍然缺乏。瞬时表达条件考察结果显示,采用宿主HEK293F细胞及PEI-40kDa转染试剂能获得35%病毒PCV2 Capsid基因细胞转染效率。转染试剂PEI(Polyethylenimine)与DNA比例差异会影响复合物形成大小及形态,复合物形成15~80 nm颗粒有利于转染效率的提高。实验以免疫逃逸型猪圆环病毒2b型NDSU41513病毒株,设计了新型PCV2 Capsid (△1-41aa)-Fc(pig) protein(PCFP)分子。在3 L反应器中成功实现了HEK293F细胞瞬时表达PCFP,表达水平达到3.8 mg/L。PCFP蛋白能够自主装形成约为41 nm类病毒颗粒,诱导小鼠机体内产生强烈的体液免疫反应,具有很高的应用潜力。

伪狂犬病病毒研究进展

伪狂犬病是由伪狂犬病病毒(pesudorabies virus,PRV)感染引起的一种严重的传染性病毒病,主要引起猪的繁殖失败、生长停滞和呼吸系统障碍,2周龄以下仔猪死亡率高达100%。伪狂犬病属于多种动物共患传染病,主要经口、鼻感染,通过在上呼吸道上皮细胞中的复制,进一步感染神经系统和内脏器官。PRV有11种糖蛋白分子,在病毒的毒力、感染入侵和致病过程中发挥重要作用。临床上采用疫苗免疫和鉴别诊断相结合的方式进行PRV的防控,起到了一定的效果,但是仍然给养猪业造成巨大损失。因此,本文综述和讨论了猪伪狂犬病的临床症状以及病原的分子特征、致病机制和疫苗研究的最新进展,以期为该病疫苗研究和诊断试剂开发提供参考。

猪伪狂犬病疫苗效力评价方法比较研究

猪伪狂犬病是一种严重危害养猪业的急性病毒性传染病,疫苗免疫是其防控的有效手段。目前正式通过注册生产上市的产品有14个,涉及10个毒株,其效力评价方法及标准不统一。就猪伪狂犬病疫苗的效力评价方法进行比较研究,以期为进一步规范疫苗效力评价方法、建立通用质量标准提供思路。

PEDV乳酸菌工程菌株对小鼠的免疫效果研究

本研究以引起猪流行性腹泻的猪流行性腹泻病毒(Porcine epidemic diarrhea virus,PEDV)为研究目标,利用含有PEDV S基因的植物乳杆菌活载体菌株LP1522-PEDS口服免疫小鼠,应用ELISA试验检测免疫小鼠粪便中SIgA含量、血清中IgG、IL-4、IL-2和IFN-γ含量,评价乳酸菌重组菌株LP1522-PEDS对小鼠的免疫效果。结果表明,首次免疫后,商品灭活疫苗组和工程菌株免疫组粪便中的SIgA、血清中的IgG、IL-4、IL-2和IFN-γ含量较对照组显著升高(P<0.05)。在免疫42~56 d,灭活疫苗组和重组菌株组抗体水平均达到最大值,抗体和免疫因子水平依次为:商品灭活疫苗组>LP1522-PEDS组>空载组≈对照组。随后商品灭活疫苗组、LP1522-PEDS组抗体和免疫因子水平逐渐下降。免疫70 d,商品灭活疫苗组抗体水平降幅度相对较小,工程菌株免疫组降幅较大。结果表明,小鼠口服携带PEDV S基因的基因工程植物乳杆菌LP1522-PEDS后能够诱导机体产生PEDV免疫应答。