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1.
目的 评价在接种两剂已上市新冠病毒灭活疫苗的人群中序贯加强免疫重组新型冠状病毒疫苗(CHO细胞)后的免疫原性和安全性,为制定新型冠状病毒疫苗的加强免疫策略提供科学依据。 方法 采用开放性试验设计,筛选入组360例已接种两剂新冠病毒灭活疫苗3~4个月、6~8个月、11~13个月的18周岁及以上研究对象并接种1剂重组新型冠状病毒疫苗(CHO细胞)。采集所有研究对象研究用疫苗接种前、接种后14 d血样,用于体液免疫检测,收集研究用疫苗接种后1个月内的所有不良事件。 结果 本研究入组360例研究对象,按研究对象加强免疫与基础免疫间隔时间分3组(A组91~120 d,B组181~240 d,C组331~390 d),各组120例,无研究对象脱落。三组年龄均值分别为38.13、40.22和45.73岁,各组间年龄差异有统计学意义(F=13.516,P<0.001),A、B组差异无统计学意义(P=0.168),C组和A、B组间差异均有统计学意义(P<0.001)。三组 IgG GMC(几何平均浓度)免疫前分别为4.81、4.23、2.12 AU/ml,差异有统计学意义(F=10.054,P<0.001),C组和A、B组间差异均有统计学意义(P<0.001),A、B组间差异无统计学意义(P=0.520);三组免疫后 IgG GMC 分别为106.69、124.05、80.04 AU/ml,差异无统计学意义(F=2.028,P=0.133)。三组 IgG 抗体阳转率分别为84.17%、87.50%、79.17%,差异无统计学意义(χ2=3.081,P=0.214)。免疫前血清针对Delta变异株和原型株不同组别的中和抗体滴度比较,三组原型株中和抗体GMT(几何平均滴度)为1∶2.18、1∶2.18、1∶2.19,差异无统计学意义(F=0.011,P=0.990);三组Delta变异株中和抗体GMT为1∶2.09、1∶2.17、1∶2.16,差异无统计学意义(F=0.378,P=0.686)。免疫后血清三组原型株中和抗体 GMT为1∶31.09、1∶34.90、1∶21.98,差异无统计学意义(F=2.262,P=0.106);三组Delta变异株中和抗体GMT为1∶61.46、1∶77.44、1∶43.71,差异无统计学意义(F=2.105,P=0.123)。序贯加强免疫后血清对新型冠状病毒Delta变异株和原型株的中和抗体阳转率分别达到82.78%、83.33%。三组 SARS-CoV-2原型株中和抗体阳转率分别为86.67%、87.50%、75.83%,差异有统计学意义(χ2=7.320,P=0.026),其中C组低于A组和B组;三组 SARS-CoV-2 Delta变异株中和抗体阳转率分别为87.50%、84.17%、76.67%,差异无统计学意义(χ2=5.183,P=0.075)。发生不良事件人数为124人,不良事件总体发生率为34.44%。各组发生率分别为35.83%、40.83%和26.67%,差异无统计学意义(χ2=5.487,P=0.064),所有研究对象出现的不良事件以接种部位不良事件为主,主要表现为疫苗接种部位疼痛(23.89%);全身不良事件主要表现为疲劳/乏力(6.94%),未发生与疫苗接种有关的SAEs。结论 接种两剂新型冠状病毒灭活疫苗后序贯加强免疫重组新型冠状病毒疫苗(CHO细胞)具有良好的免疫原性和安全性。较长间隔期的免疫前IgG和免疫后原型株中和抗体阳转率较低,不同间隔期的免疫后IgG 、Delta变异株和原型株中和抗体水平比较差异均无统计学意义,建议基础免疫后6~8个月为最佳的接种间隔。  相似文献   
2.
Although antibody levels progressively decrease following SARS-CoV-2 infection, the immune memory persists for months. Thus, individuals who naturally contracted SARS-CoV-2 are expected to develop a more rapid and sustained response to COVID-19 vaccines than naïve individuals. In this study, we analyzed the dynamics of the antibody response to the BNT162b2 mRNA COVID-19 vaccine in six healthcare workers who contracted SARS-CoV-2 in March 2020, in comparison to nine control subjects without a previous infection. The vaccine was well tolerated by both groups, with no significant difference in the frequency of vaccine-associated side effects, with the exception of local pain, which was more common in previously infected subjects. Overall, the titers of neutralizing antibodies were markedly higher in response to the vaccine than after natural infection. In all subjects with pre-existing immunity, a rapid increase in anti-spike receptor-binding domain (RBD) IgG antibodies and neutralizing antibody titers was observed one week after the first dose, which seemed to act as a booster. Notably, in previously infected individuals, neutralizing antibody titers 7 days after the first vaccine dose were not significantly different from those observed in naïve subjects 7 days after the second vaccine dose. These results suggest that, in previously infected people, a single dose of the vaccine might be sufficient to induce an effective response.  相似文献   
3.
Background: The BNT162b2 mRNA COVID-19 vaccine has been administered to children and adolescents with cancer and hematologic diseases since they are at high risk of manifesting severe symptoms if they have COVID-19 infection but the adequate immune response after vaccination in these immunocompromised patients are questionable.Objective: To evaluate the immune response of children and adolescents with cancer and hematologic diseases after receiving 2 doses of the BNT162b2 mRNA COVID-19 vaccine. Methods: This is a prospective cohort study of patients with cancer and hematologic disease, who aged 12- 18 years old and received 2 doses the BNT162b2 vaccines at 4 weeks apart were enrolled. Immunogenicity was determined by measuring serum anti-SARS-CoV-2 immunoglobulin antibodies directed against the receptor binding domain (RBD) of S1 domain of the spike protein (Anti S-RBD), surrogated viral neutralization test (sVNT) of SARS-CoV-2 and Delta strain. Blood samples were collected and analyzed at 4 and 12 weeks after vaccination. The seroprotective rate was defined as sVNT ≥ 68%. Results: From Oct 2021 to Jan 2022, 43 children were enrolled, 21 were on-therapy and 22 were off-therapy. 25 were hematologic malignancy, 15 solid tumor and 3 hematologic diseases with immunosuppressive drugs. The GMT (95%CI) of a anti S-RBD IgG level at 4 weeks after vaccination were 56.05 (13.2,238.2) and 3633 (2689,4908) BAU/mL in on-therapy and off-therapy group, respectively, p<0.001. The sVNT (95%CI) of delta strain were 26% (5.85-73.55%) and 97.05% (96.0-97.4%) as the seroprotective level which were 33.3% in on-therapy group and 100% in off-therapy group (p<0.001). 14 children in on-therapy group need an additional dose. Conclusion: After complete vaccination, the seroprotective rate and antibody level in pediatric and adolescent patients with cancer and hematologic disease who receive immunosuppressive agents are quite low, compared with patients who had complete treatment. Additional dose of primary series should be offered.  相似文献   
4.
目的:探讨活化转录因子 6(ATF6)对骨肉瘤细胞 MCA205 免疫原性的影响,初步解析其调控机制。方法:利用CRISPR-Cas9技术敲除MCA205细胞的Atf6基因,借助CCK-8实验、细胞能量代谢检测、流式细胞术、ATP检测试剂盒、干扰素刺激响应元件(ISRE)-荧光素酶报告细胞实验和qPCR法分别检测野生型(WT)和Atf6-/- MCA205细胞在PBS或衣霉素(Tm)处理后的活力、线粒体耗氧速率(OCR)和胞外酸化速率(ECAR)、磷脂酰丝氨酸外翻和细胞膜通透性、胞内钙离子动员、胞内外ATP浓度、IFN-a/b分泌和干扰素刺激基因(ISG)的表达水平。在免疫系统健全的小鼠皮下接种WT或Atf6-/- MCA205细胞,比较两者的成瘤速度、肿瘤组织基因转录图谱、局部抗肿瘤效应T细胞活化有无差异。将WT和Atf6-/- MCA205细胞分别接种于nu/nu小鼠背部两侧皮下,或将Atf6-/- MCA205细胞分别接种于免疫系统健全小鼠和Ifnar-/-小鼠皮下,记录肿瘤生长曲线。分别用Tm预处理的WT和Atf6-/- MCA205细胞对na?ve小鼠(未经免疫刺激的小鼠)进行初次免疫,使肿瘤抗原特异性T细胞发生初次活化(prime),随后收集引流淋巴结细胞并进行体外再刺激(boost),分析特异性T细胞再次活化有无差异。按照不同的效靶比,将NK细胞与染料标记的WT和Atf6-/- MCA205细胞共培养,流式细胞术检测细胞杀伤情况。结果:PBS或Tm处理后,WT和Atf6-/-骨肉瘤细胞活力和增殖、氧化磷酸化和糖酵解、离子霉素触发的胞内钙离子动员、胞内外ATP和IFN-a/b分泌均无显著差异。Tm处理后,Atf6-/-细胞死亡比例低于WT细胞(P<0.01)。在免疫系统健全的小鼠体内,Atf6-/-肿瘤的生长速度明显低于WT肿瘤(P<0.05)。然而,在缺乏T细胞的nu/nu小鼠体内,两种肿瘤生长速度的差异显著缩小。与免疫系统健全的小鼠相比,Ifnar-/-小鼠体内Atf6-/-肿瘤的生长速度略快(P<0.05)。Atf6-/-肿瘤内免疫应答相关基因的表达、效应T细胞的活化均显著高于WT肿瘤(P<0.05)。与WT MCA205细胞相比,Atf6-/- MCA205细胞与NK细胞共培养后死亡比例更高(P<0.05)。在Tm刺激后,Atf6-/- MCA205细胞比WT细胞表达更多的Irf3和Irf7,前者在prime-boost实验中可刺激T细胞分泌更多的IFN-g。结论:阻断ATF6信号通路能显著增强MCA205细胞的免疫原性,促进免疫监视,阻碍肿瘤进展。  相似文献   
5.
6.
目的 以腺病毒5型载体(Ad5)构建含寨卡病毒(ZIKV)包膜蛋白(prM-E)的复制缺陷型5型重组腺病毒(rAd5)表达载体,测定prM-E在细胞中的表达及对小鼠的免疫原性。方法 从ZIKV毒株Z16006(亚洲型)分离获得prM-E基因片段,以重组腺病毒AdMaxTM系统包装重组腺病毒rAd5/prM-E。选用C57BL/6小鼠,以rAd5/prM-E 107、108和109 PFU三个剂量肌内注射免疫小鼠,在第3周同等剂量加强免疫一次,第5周从小鼠眼球取血并分离脾淋巴细胞。分别以ELISpot和ELISA方法测定小鼠对ZIKV prM-E的体液与细胞免疫反应。结果 成功构建复制缺陷型重组腺病毒载体rAd5/prM-E,采用Western blot方法和抗ZIKV E抗体检测rAd5/prM-E感染的293A细胞表达产物,可见与E蛋白相应的56 kDa蛋白带。以ELISpot方法测定小鼠脾淋巴细胞特异性IFN-γ分泌细胞形成斑点数(SFCs),结果分别为(688.54±186.43)、(1 084.90±144.14)和(1 640.20±147.13) SFCs/106脾细胞,与病毒接种剂量呈正比关系;采用ELISA测定免疫小鼠血清中抗E抗体,其滴度(log10值)分别为(3.14±0.39)、(3.50±0.30)和(3.74±0.25), 均高于对照组小鼠(0.80±0.17),差异具有统计学意义(P<0.001)。结论 rAd5/prM-E具有感染小鼠并诱导小鼠产生强烈的特异性抗体和细胞免疫反应的能力,表明prM-E具有良好的免疫原性,为ZIKV候选疫苗研制提供了可靠的免疫源。  相似文献   
7.
《Vaccine》2016,34(46):5488-5494
DNA vaccines are ideal candidates for global vaccination purposes because they are inexpensive and easy to manufacture on a large scale such that even people living in low-income countries can benefit from vaccination. However, the potential of DNA vaccines has not been realized owing mainly to the poor cellular uptake of DNA in vivo resulting in the poor immunogenicity of DNA vaccines. In this review, we discuss the benefits and shortcomings of several promising and innovative non-biological methods of DNA delivery that can be used to increase cellular delivery and efficacy of DNA vaccines.  相似文献   
8.
9.
The immune response against hapten is T‐cell‐dependent, and so requires the uptake, processing and presentation of peptides on MHC class II molecules by antigen‐presenting cells to the specific T cell. Some haptens, following conjugation to the available free amines on the surface of the carrier protein, can reduce its immunogenicity. The purpose of this study was to explore the mechanism by which this occurs. Four proteins were tested as carriers and six molecules were used as haptens. The immune response to the carrier proteins was reduced > 100‐fold by some of the haptens (termed carrier immunogenicity reducing haptens – CIRH), whereas other haptens did not influence the protein immunogenicity (carrier immunogenicity non‐reducing haptens – nCIRH). Conjugation of the protein to a CIRH affected protein degradation by lysosomal cathepsins, leading to the generation of peptides that differ in length and sequence from those derived from the same native protein or that protein modified with nCIRH. Injection of CIRH‐conjugated protein into mice induced an increase in the population of regulatory T cells. The results of this study provide a putative mechanism of action for the reduction of immune response to haptenated proteins.  相似文献   
10.
Recent data suggest that HLA epitope matching is beneficial for the prevention of de novo donor specific antibody (DSA) formation after transplantation. In this review, different approaches to predict the immunogenicity of an HLA mismatch will be discussed. The parameters used in these models are often called epitopes but the actual antibody epitope is far more complex. Exact knowledge of the antibody epitope is crucial if epitope matching is also used as a tool to select compatible donors for (highly) sensitized patients. Evidence is provided that it is not always possible to give an exact definition of an antibody epitope. We conclude that HLA “epitope” matching is superior over HLA antigen matching with respect to the prevention of de novo DSA formation and will enhance the prediction of acceptable HLA mismatches for sensitized patients. However, epitope matching at our current level of knowledge will not solve all histocompatibility problems as unexpected antibody reactivity still may occur.  相似文献   
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