Immunogenicity and safety levels of inactivated quadrivalent influenza vaccine in healthy adults via meta-analysis.

Objective: The aim of the current study was to evaluate immunogenicity and safety levels of human inactivated quadrivalent influenza vaccine (QIV) which includes two A strains (A/H1N1, A/H3N2) and two B lineages (B/Victoria, B/Yamagata) in healthy adults via meta-analysis. Methods: Searches were conducted in PubMed, Cochrane Library, ClinicalTrials.gov, and EMBASE databases published in 2011-2020 according to inclusion and exclusion criteria. The purpose was to collect and perform meta-analysis of related randomized clinical trial (RCT) data concerning safety and immunogenicity levels of human QIV compared with inactivated trivalent influenza vaccine (TIV). Results: A total of 9 literatures were included. There was no significant difference in the seroconversion(SCR) and seroprotection(SPR) between QIV and TIV for influenza A strains (A/H1N1, A/H3N2) and the B lineage included in the TIV. QIV showed superior efficacy for the B lineage not included in the TIV: SCR RR of 2.20 (95%CI: 1.44-3.37, p = .0003) and SPR RR of 1.34 (95%CI: 1.10-1.63, p = .004) for B/Victoria, and SCR RR of 1.88 (95%CI: 1.53-2.31, p < .00001) and SPR RR of 1.11 (95%CI: 1.03-1.19, p = .006) for B/Yamagata, respectively. There were no significant differences between QIV and TIV for local and systemic adverse events(AE) post-vaccination. Conclusion: In adults 18-64 years old, QIV not only produced similar immunogenicity and safety levels to TIV, but also had better immunogenicity against influenza B vaccine strains not included in TIV.

A simple and safe antibody neutralization assay based on polio pseudoviruses.

The evaluation of the immunogenicity of Sabin strain based Inactivated Poliovirus Vaccines (sIPV) necessitates the use of wild strains in neutralization assays to assess the potential cross-reactivity of antibodies. The live virus strains including wild and Sabin strains must be handled in level 3 biocontainment laboratories. To develop an alternative assay without the use of a live virus, we constructed Mahoney, MEF-1, and Saukett pseudovirions by inserting luciferase reporter genes into intact capsid proteins. Afterward, we developed a pseudovirus-based neutralization test (pNT) and evaluated for the specificity and reproducibility. We tested serum samples from a clinical trial on sIPV vaccines by pNT and compared the results with those obtained from conventional neutralization tests (cNT). A strong correlation was observed between two methods, with the correlation coefficients of all three types of IPV vaccines being greater than 0.82 (p < 0.0001). The Geometric Mean Titer (GMT) values obtained by pNT were approximately four times higher than that by cNT, revealing the better sensitivity of pNT. In conclusion, pNT is a safe, rapid and sensitive quantitative assay with the potential of being an alternative for the evaluation of the potency of polio vaccines.

Safety and effectiveness assessment of 2011-2012 seasonal influenza vaccine produced in China: a randomized trial.

OBJECTIVE: This study evaluated the effectiveness and safety of the egg-based, trivalent, inactivated split influenza vaccine produced by the Institute of Medical Biology, Chinese Academy of Medical Sciences, Peking Union Medical College, China. METHODS: From March 2012 through May 2012, we enrolled a total of 1390 healthy volunteers between the ages of 3 and 80 years in a randomized clinical trial at the Hebei Disease Control Center Vaccine Clinical Evaluation Center. For all subjects, body part adverse reactions and whole-body adverse reactions were observed 30 min, 6 h, and 1-7 days' post-inoculation. If no severe adverse effects were observed 7 days' post-vaccination, the local and systemic reactions of preliminary test participants were recorded until day 28. There was no placebo group in this study. Blood samples were taken for serological testing before vaccination and 28 days' post-vaccination. RESULTS: Twenty-eight days after vaccination, the seroconversion rates of experimental and control groups were H1N1 75.3% and 75.7%, H3N2 75.8% and 71.8%, B 70.7% vs. 69.4%, (P > 0.05). The antibody Geometric Mean Titer（GMT）of experimental and control groups were H1N1 (179.7, 182.4), H3N2 (584.0, 445.7), B (201.4,191.6). The protection rate of experimental and control groups was not statistically significant (H1N1: 86% vs. 87%, H3N2: 99% vs. 98%, B: 98% vs. 98%). Also, 95% confidence intervals of the protection rate difference between the experimental and the control group were H1N1: -0.1% (-4.1,3.8) %, H3N2: 0.3% (-1.0,1.7) % and B: 0.2% (-1.5,1.9) %; confidence intervals exceeded the limit of -5%. The rates of adverse reactions between experimental and control groups were 6.3% and 7.7% in local response reactions, and 19.5% and 18.0% in systemic reactions. Three hundred and twenty-seven adverse events (AEs) in 1200 (27.76%) subjects were reported within 28 d after vaccination. No serious adverse events occurred during the study. CONCLUSIONS: The experimental vaccine three-antibody protection rate was non-inferior to the control vaccine. Our results demonstrated that the experimental vaccine achieved the primary immunogenic end point of the intended clinical protocol, as well as a secondary immunogenic end-point, with an acceptable level of safety. IRB approval for this study was issued under #2012Y0005 and registered as Clinical Trial No. NCT01551810.

Prokaryotic soluble expression of protein D of Haemophilus influenzae type b / 中华实验和临床病毒学杂志

<p><b>OBJECTIVE</b>To express the recombinant D protein in prokaryotic expression system solubly and make preparation for producing D-carrier conjugate vaccine next step.</p><p><b>METHODS</b>The hpd gene fragment removed of signal peptide from genomic DNA of Hib CMCC was inserted into pET43. 1a. The recombinant plasmid was transformed to competent E. coli BL21 (DE3) for expression under induction of IPTG. The expressed recombination protein was precipitated with ammonium sulfate, purified by DEAE anion exchange column chromatography and identified for reactogenicity by Western Blot.</p><p><b>RESULTS</b>The expressed recombination protein, in a soluble form, constained about 50% of total somatic protein and showed specific reaction with the HIB antisera after preliminary purification.</p><p><b>CONCLUSION</b>The D protein recombined expression plasmid was constructed successfully and expressed D protein in prokaryotic cells in a solube form.</p>

Preparation of vero cell-adapted influenza H5N1 virus strain by genetic reassortment / 中华实验和临床病毒学杂志

<p><b>OBJECTIVE</b>To prepare Vero cell-adapted influenza H5N1 virus strain by Genetic Reassortment and produce influenza H5N1 vaccine using Vero cell as a substrate.</p><p><b>METHODS</b>Embryonated specific pathogen-free (SPF) hen's eggs and Vero cells were co-infected with Vero cell-adapted influenza virus A/Yunnan/1/2005 Va(H3N2) and A/Anhui/1/2005 (H5N1) via reverse genetics. The reassortant was screened with goat antibody against strain A/Yunnan/1/2005 Va(H3N2) and identified for subtype by hemagglutination-inhibition (HI) assays and gene analysis of HA and NA.</p><p><b>RESULTS</b>A Vero cell-adapted influenza H5N1 virus strain was obtained, and there was no significant difference in serum antibody titers of monovalent inactivated vaccine reassorted before and after (F = 0.857, P > 0.05).</p><p><b>CONCLUSION</b>The Vero cell-adapted influenza virus of epidemic strain may be reassortment between Vero cell-adapted and epidemic strains.</p>

Research on an improved Lowry method to determine content of protein in Sabin IPV / 中华实验和临床病毒学杂志

<p><b>OBJECTIVE</b>To establish a method for the content determination of protein in Sabin IPV.</p><p><b>METHODS</b>Using lowry method combined with being precipitated by trichloroacetic acid to determine the content of protein in Sabin IPV. Changing different conditions to optimize the experiment to establish a improved lowry method. And the sample recovery test was also conducted.</p><p><b>RESULTS</b>The method can exclude the interference of free aminoacid, phenols and some other additives. The calibration curve was in good linearity of protein within the range of 2.5 microg/ml-40 Microg/ml, r = 0.9998. Under the best conditions, the mean recovery was 95.32%, the CV in a batch and between batches were both < 10%.</p><p><b>CONCLUSION</b>The method can be used to determine the micro content of protein in vaccines.</p>

Effective inactivatian test of inactivated hepatitis A vaccine using integrated cell culture/strand-specific reverse transcriptase-polymerase chain reaction / 中华实验和临床病毒学杂志

<p><b>OBJECTIVE</b>To establish an quick, sensitive and specific assay for effective inactivatian test of inactivated hepatitis A vaccine.</p><p><b>METHODS</b>effective inactivatian test of inactivated hepatitis A vaccine were carried out using integrated cell culture/strand-specific RT-PCR (ICC/strand-specific RT-PCR) assay compared with traditional ELISA and nest RT-PCR assay.</p><p><b>RESULTS</b>all the samples were infectious negative detecting by both ICC/ strand-specific RT-PCR and ELISA assay,while some samples appeared false positive detecting by nest RT-PCR.</p><p><b>CONCLUSION</b>ICC/strand-specific RT-PCR assay is a novel, rapid, sensitive and reliable method for effective inactivatian test of inactivated hepatitis A vaccine. Shorting detection period largely, this assay may be used as an alternative method for routine inactivated hepatitis A vaccines test.</p>

Effect of 2-phenoxyethanol on potency of Sabin inactivated poliomyelitis vaccine and its safety / 中华实验和临床病毒学杂志

<p><b>OBJECTIVE</b>To investigate the effect of 2-phenoxyethanol on potency of Sabin inactivated poliomyelitis vaccine (IPV).</p><p><b>METHODS</b>Sabin IPV samples containing 5 mg or 7 mg 2-phenoxyethanol each dosage respectively were placed separately at 4 degrees C, 37 degrees C for 2 days and 7 days. D-antigen contents were tested with ELISA method. Then neutralizing antibodies in mice and guinea pigs were detected. The safety experiment was performed according to unusual toxicity test of China requirement for biological product.</p><p><b>RESULTS</b>After addition of 2-phenoxyethanol, the I, II, and III D-antigen contents of Sabin IPV did not change. The antibody levels in mice and guinea pigs were not different between experimental group and control group. Animals were safe during observation period.</p><p><b>CONCLUSION</b>2-Phenoxyethanol had no effect on potency and safety of Sabin IPV. It can be used as antiseptic for Sabin IPV.</p>

Construction of bicistronic vector and its application to combined DNA vaccine / 中华实验和临床病毒学杂志

<p><b>BACKGROUND</b>To study preparation of polyvalent DNA vaccine and the control of multiple gene expression.</p><p><b>METHODS</b>A bicistronic vector pcDNA3.0BA was constructed from pcDNA3.0. HCV PC154 gene and HBV preS2S gene were inserted into this vector to form bicistronic expression construct pcDNA3.0BAPC154S2S and monocistronic expression construct pcDNA3.0BAPC154 or pcDNA3.0BAS2S. These plasmids were transiently expressed in COS-7 cells and injected into muscles of BALB/c mice.</p><p><b>RESULTS</b>pcDNA3.0BA contains two cistronic units, which can co-express two kinds of genes, with the first immunogen gene and the second gene serving as additional immunogen or as modulator for the immune responses. HBV surface Ag and HCV core Ag were coexpressed in vitro. The antibody responses and lymphoproliferation to antigens were similar between bicistronic and monocistronic expression construct in mice.</p><p><b>CONCLUSION</b>pcDNA3.0BA is a novel vector, which can coexpress two proteins and elicit polyvalent immune responses.</p>

Expression and self-assembly of HCV structural proteins into virus-like particles and their immunogenicity / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>The synthesis of virus-like particles (VLPs) provides an important tool to determine the structural requirements for viral particle assembly and virus-host interactions. Our purpose was to express simultaneously all three structural proteins of hepatitis C virus (HCV) in insect cells to investigate the proteins assembly into VLPs and the immunogenicity of these particles.</p><p><b>METHODS</b>HCV gene sequences encoding the structural proteins C, E1, and E2 were amplified with PCR, and recombinant baculoviruses were constructed using recombinant DNA techniques. The expression of HCV structural proteins in insect cells was analyzed by immunofluorescence and SDS-PAGE. The interaction of expressed structural proteins was investigated by immunoprecipitation and immunoblotting. The VLPs in the insect cells were visualized by electron microscopy (EM). VLPs were then purified by sucrose gradient centrifugation and used to immunize BALB/c mice. Antibodies against HCV were tested for in mouse serum samples by an ELISA assay.</p><p><b>RESULTS</b>The recombinant baculoviruses reBV/C and reBV/E1-E2 were constructed successfully. Insect cells co-infected with reBV/C and reBV/E1-E2 expressed HCV C, E1, and E2 proteins with the expected molecular weights of 20kD, 35kD, and 66kD, respectively. The results of immunoprecipitation and immunoblotting assays revealed the coimmunoprecipitation of C, E1, and E2 proteins, indicating association of the three structural proteins. Electron microscopy of insect cells co-infected with reBV/C and reBV/E1-E2 demonstrated spherical particles (40 to 60 nm in diameter) similar to the HCV virions from serum samples or hepatic tissue samples of HCV infected humans. The VLPs were partially purified. Antibodies to HCV were detectable in the serum of mice immunized with VLPs.</p><p><b>CONCLUSION</b>HCV structural proteins simultaneously expressed in insect cells can interact with each other and assemble into HCV-like particles, which are shown to be immunogenic in mice.</p>