Safety and immunogenicity of a multivalent HIV vaccine comprising envelope protein with either DNA or NYVAC vectors (HVTN 096): a phase 1b, double-blind, placebo-controlled trial.
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SUBMITTER: Pantaleo G
PROVIDER: S-EPMC7156919 | biostudies-literature |
REPOSITORIES: biostudies-literature
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Project description:Increasing the breadth of human immunodeficiency virus type 1 (HIV-1) vaccine-elicited immune responses or targeting conserved regions may improve coverage of circulating strains. HIV Vaccine Trials Network 083 tested whether cellular immune responses with these features are induced by prime-boost strategies, using heterologous vectors, heterologous inserts, or a combination of both.A total of 180 participants were randomly assigned to receive combinations of adenovirus vectors (Ad5 or Ad35) and HIV-1 envelope (Env) gene inserts (clade A or B) in a prime-boost regimen.T-cell responses to heterologous and homologous insert regimens targeted a similar number of epitopes (ratio of means, 1.0; 95% confidence interval [CI], .6-1.6; P = .91), but heterologous insert regimens induced significantly more epitopes that were shared between EnvA and EnvB than homologous insert regimens (ratio of means, 2.7; 95% CI, 1.2-5.7; P = .01). Participants in the heterologous versus homologous insert groups had T-cell responses that targeted epitopes with greater evolutionary conservation (mean entropy [±SD], 0.32 ± 0.1 bits; P = .003), and epitopes recognized by responders provided higher coverage (49%; P = .035). Heterologous vector regimens had higher numbers of total, EnvA, and EnvB epitopes than homologous vector regimens (P = .02, .044, and .045, respectively).These data demonstrate that vaccination with heterologous insert prime boosting increased T-cell responses to shared epitopes, while heterologous vector prime boosting increased the number of T-cell epitopes recognized.NCT01095224.
| S-EPMC4721914 | biostudies-literature
Project description:As part of the continuing effort to develop an effective HIV vaccine, we generated a poxviral vaccine vector (previously described) designed to improve on the results of the RV144 phase III clinical trial. The construct, NYVAC-KC, is a replication-competent, attenuated recombinant of the vaccinia virus strain NYVAC. NYVAC is a vector that has been used in many previous clinical studies but is replication deficient. Here, we report a side-by-side comparison of replication-restricted NYVAC and replication-competent NYVAC-KC in a nonhuman primate study, which utilized a prime-boost regimen similar to that of RV144. NYVAC-C and NYVAC-C-KC express the HIV-1 antigens gp140, and Gag/Gag-Pol-Nef-derived virus-like particles (VLPs) from clade C and were used as the prime, with recombinant virus plus envelope protein used as the boost. In nearly every T and B cell immune assay against HIV-1, including neutralization and antibody binding, NYVAC-C-KC induced a greater immune response than NYVAC-C, indicating that replication competence in a poxvirus may improve upon the modestly successful regimen used in the RV144 clinical trial.IMPORTANCE Though the RV144 phase III clinical trial showed promise that an effective vaccine against HIV-1 is possible, a successful vaccine will require improvement over the vaccine candidate (ALVAC) used in the RV144 study. With that goal in mind, we have tested in nonhuman primates an attenuated but replication-competent vector, NYVAC-KC, in direct comparison to its parental vector, NYVAC, which is replication restricted in human cells, similar to the ALVAC vector used in RV144. We have utilized a prime-boost regimen for administration of the vaccine candidate that is similar to the one used in the RV144 study. The results of this study indicate that a replication-competent poxvirus vector may improve upon the effectiveness of the RV144 clinical trial vaccine candidate.
| S-EPMC6340019 | biostudies-literature
Project description:A preventive human immunodeficiency virus type 1 (HIV-1) vaccine is an essential part of the strategy to eradicate AIDS. A critical question is whether antibodies that do not neutralize primary isolate (tier 2) HIV-1 strains can protect from infection. In this study, we investigated the ability of an attenuated poxvirus vector (NYVAC) prime-envelope gp120 boost to elicit potentially protective antibody responses in a rhesus macaque model of mucosal simian-human immunodeficiency virus (SHIV) infection. NYVAC vector delivery of a group M consensus envelope, trivalent mosaic envelopes, or a natural clade B isolate B.1059 envelope elicited antibodies that mediated neutralization of tier 1 viruses, cellular cytotoxicity, and phagocytosis. None of the macaques made neutralizing antibodies against the tier 2 SHIV SF162P3 used for mucosal challenge. Significant protection from infection was not observed for the three groups of vaccinated macaques compared to unvaccinated macaques, although binding antibody to HIV-1 Env correlated with decreased viremia after challenge. Thus, NYVAC Env prime-gp120 boost vaccination elicited polyfunctional, nonneutralizing antibody responses with minimal protective activity against tier 2 SHIV mucosal challenge.IMPORTANCE The antibody responses that confer protection against HIV-1 infection remain unknown. Polyfunctional antibody responses correlated with time to infection in previous macaque studies. Determining the ability of vaccines to induce these types of responses is critical for understanding how to improve upon the one efficacious human HIV-1 vaccine trial completed thus far. We characterized the antibody responses induced by a NYVAC-protein vaccine and determined the protective capacity of polyfunctional antibody responses in an R5, tier 2 mucosal SHIV infection model.
| S-EPMC5874432 | biostudies-literature
Project description:UnlabelledAn effective human immunodeficiency virus type 1 (HIV-1) vaccine must induce protective antibody responses, as well as CD4(+) and CD8(+) T cell responses, that can be effective despite extraordinary diversity of HIV-1. The consensus and mosaic immunogens are complete but artificial proteins, computationally designed to elicit immune responses with improved cross-reactive breadth, to attempt to overcome the challenge of global HIV diversity. In this study, we have compared the immunogenicity of a transmitted-founder (T/F) B clade Env (B.1059), a global group M consensus Env (Con-S), and a global trivalent mosaic Env protein in rhesus macaques. These antigens were delivered using a DNA prime-recombinant NYVAC (rNYVAC) vector and Env protein boost vaccination strategy. While Con-S Env was a single sequence, mosaic immunogens were a set of three Envs optimized to include the most common forms of potential T cell epitopes. Both Con-S and mosaic sequences retained common amino acids encompassed by both antibody and T cell epitopes and were central to globally circulating strains. Mosaics and Con-S Envs expressed as full-length proteins bound well to a number of neutralizing antibodies with discontinuous epitopes. Also, both consensus and mosaic immunogens induced significantly higher gamma interferon (IFN-γ) enzyme-linked immunosorbent spot assay (ELISpot) responses than B.1059 immunogen. Immunization with these proteins, particularly Con-S, also induced significantly higher neutralizing antibodies to viruses than B.1059 Env, primarily to tier 1 viruses. Both Con-S and mosaics stimulated more potent CD8-T cell responses against heterologous Envs than did B.1059. Both antibody and cellular data from this study strengthen the concept of using in silico-designed centralized immunogens for global HIV-1 vaccine development strategies.ImportanceThere is an increasing appreciation for the importance of vaccine-induced anti-Env antibody responses for preventing HIV-1 acquisition. This nonhuman primate study demonstrates that in silico-designed global HIV-1 immunogens, designed for a human clinical trial, are capable of eliciting not only T lymphocyte responses but also potent anti-Env antibody responses.
| S-EPMC4474309 | biostudies-literature
Project description:Objective:In vitro, in vivo, and open-label studies suggest that interferon gamma (IFN-γ 1b) may improve clinical features in Friedreich Ataxia through an increase in frataxin levels. The present study evaluates the efficacy and safety of IFN-γ 1b in the treatment of Friedreich Ataxia through a double-blind, multicenter, placebo-controlled trial. Methods:Ninety-two subjects with FRDA between 10 and 25 years of age were enrolled. Subjects received either IFN-γ 1b or placebo for 6 months. The primary outcome measure was the modified Friedreich Ataxia Rating Scale (mFARS). Results:No difference was noted between the groups after 6 months of treatment in the mFARS or secondary outcome measures. No change was noted in buccal cell or whole blood frataxin levels. However, during an open-label extension period, subjects had a more stable course than expected based on natural history data. Conclusions:This study provides no direct evidence for a beneficial effect of IFN-γ1b in FRDA. The modest stabilization compared to natural history data leaves open the possibility that longer studies may demonstrate benefit.
| S-EPMC6414489 | biostudies-literature
Project description:Integrase Defective Lentiviral Vectors (IDLVs) represent an attractive vaccine platform for delivering HIV-1 antigens, given their ability to induce specific and persistent immune responses in both mice and non-human primates (NHPs). Recent advances in HIV-1 immunogen design demonstrated that native-like HIV-1 Envelope (Env) trimers that mimic the structure of virion-associated Env induce neutralization breadth in rabbits and macaques. Here, we describe the development of an IDLV-based HIV-1 vaccine expressing either soluble ConSOSL.UFO.664 or membrane-tethered ConSOSL.UFO.750 native-like Env immunogens with enhanced bNAb epitopes exposure. We show that IDLV can be pseudotyped with properly folded membrane-tethered native-like UFO.750 trimers. After a single IDLV injection in BALB/c mice, IDLV-UFO.750 induced a faster humoral kinetic as well as higher levels of anti-Env IgG compared to IDLV-UFO.664. IDLV-UFO.750 vaccinated cynomolgus macaques developed unusually long-lasting anti-Env IgG antibodies, as underlined by their remarkable half-life both after priming and boost with IDLV. After boosting with recombinant ConM SOSIP.v7 protein, two animals developed neutralization activity against the autologous tier 1B ConS virus mediated by V1/V2 and V3 glycan sites responses. By combining the possibility to display stabilized trimeric Env on the vector particles with the ability to induce sustained humoral responses, IDLVs represent an appropriate strategy for delivering rationally designed antigens to progress towards an effective HIV-1 vaccine.
| S-EPMC9023570 | biostudies-literature
Project description:Aims/hypothesisInfection with coxsackie B viruses (CVBs) can cause diseases ranging from mild common cold-type symptoms to severe life-threatening conditions. CVB infections are considered to be prime candidates for environmental triggers of type 1 diabetes. This, together with the significant disease burden of acute CVB infections and their association with chronic diseases other than diabetes, has prompted the development of human CVB vaccines. The current study evaluated the safety and immunogenicity of the first human vaccine designed against CVBs associated with type 1 diabetes in a double-blind randomised placebo-controlled Phase I trial.MethodsThe main eligibility criteria for participants were good general health, age between 18 and 45 years, provision of written informed consent and willingness to comply with all trial procedures. Treatment allocation (PRV-101 or placebo) was based on a computer-generated randomisation schedule and people assessing the outcomes were masked to group assignment. In total, 32 participants (17 men, 15 women) aged 18-44 years were randomised to receive a low (n=12) or high (n=12) dose of a multivalent, formalin-inactivated vaccine including CVB serotypes 1-5 (PRV-101), or placebo (n=8), given by intramuscular injections at weeks 0, 4 and 8 at a single study site in Finland. The participants were followed for another 24 weeks. Safety and tolerability were the primary endpoints. Anti-CVB IgG and virus-neutralising titres were analysed using an ELISA and neutralising plaque reduction assays, respectively.ResultsAmong the 32 participants (low dose, n=12; high dose, n=12; placebo, n=8) no serious adverse events or adverse events leading to study treatment discontinuation were observed. Treatment-emergent adverse events considered to be related to the study drug occurred in 37.5% of the participants in the placebo group and 62.5% in the PRV-101 group (injection site pain, headache, injection site discomfort and injection site pruritus being most common). PRV-101 induced dose-dependent neutralising antibody responses against all five CVB serotypes included in the vaccine in both the high- and low-dose groups. Protective titres ≥8 against all five serotypes were seen in >90% of participants over the entire follow-up period.Conclusions/interpretationThe results indicate that the tested multivalent CVB vaccine is well tolerated and immunogenic, supporting its further clinical development.Trial registrationClinicalTrials.gov NCT04690426.FundingThis trial was funded by Provention Bio, a Sanofi company.
| S-EPMC10954874 | biostudies-literature
Project description:The safety and immunogenicity of the second generation oral enterotoxigenic Escherichia coli (ETEC) vaccine ETVAX, consisting of inactivated recombinant E. coli strains over-expressing the colonization factors (CFs) CFA/I, CS3, CS5 and CS6 and the heat labile toxoid LCTBA, were evaluated in Bangladeshi volunteers. To enable analysis of antibody responses against multiple vaccine antigens for subsequent use in small sample volumes from children, a sensitive electrochemiluminescence (ECL) assay for analysis of intestine-derived antibody-secreting cell responses using the antibodies in lymphocyte secretions (ALS) assay was established using Meso Scale Discovery technology. Three groups of Bangladeshi adults (n?=?15 per group) received two oral doses of ETVAX with or without double mutant LT (dmLT) adjuvant or placebo in the initial part of a randomized, double-blind, placebo-controlled, age-descending, dose-escalation trial. CF- and LTB-specific ALS and plasma IgA responses were analyzed by ECL and/or ELISA. ETVAX was safe and well tolerated in the adults. Magnitudes of IgA ALS responses determined by ECL and ELISA correlated well (r?=?0.85 to 0.98 for the five primary antigens, P?<?0.001) and ECL was selected as the ALS readout method. ALS IgA responses against each of the primary antigens were detected in 87-100% of vaccinees after the first and in 100% after the second vaccine dose. Plasma IgA responses against different CFs and LTB were observed in 62-93% and 100% of vaccinees, respectively. No statistically significant adjuvant effect of dmLT on antibody responses to any antigen was detected, but the overall antigenic breadth of the plasma IgA response tended to favor the adjuvanted vaccine when responses to 4 or more or 5 vaccine antigens were considered. Responses in placebo recipients were infrequent and mainly detected against single antigens. The promising results in adults supported testing ETVAX in descending age groups of children. ClinicalTrials.gov Identifier: NCT02531802.
| S-EPMC6717083 | biostudies-literature
Project description:Attenuated poxviruses are safe and capable of expressing foreign antigens. Poxviruses are applied in veterinary vaccination and explored as candidate vaccines for humans. However, poxviruses express multiple genes encoding proteins that interfere with components of the innate and adaptive immune response. This manuscript describes two strategies aimed to improve the immunogenicity of the highly attenuated, host-range restricted poxvirus NYVAC: deletion of the viral gene encoding type-I interferon-binding protein and development of attenuated replication-competent NYVAC. We evaluated these newly generated NYVAC mutants, encoding HIV-1 env, gag, pol and nef, for their ability to stimulate HIV-specific CD8 T-cell responses in vitro from blood mononuclear cells of HIV-infected subjects. The new vectors were evaluated and compared to the parental NYVAC vector in dendritic cells (DCs), RNA expression arrays, HIV gag expression and cross-presentation assays in vitro. Deletion of type-I interferon-binding protein enhanced expression of interferon and interferon-induced genes in DCs, and increased maturation of infected DCs. Restoration of replication competence induced activation of pathways involving antigen processing and presentation. Also, replication-competent NYVAC showed increased Gag expression in infected cells, permitting enhanced cross-presentation to HIV-specific CD8 T cells and proliferation of HIV-specific memory CD8 T-cells in vitro. The recombinant NYVAC combining both modifications induced interferon-induced genes and genes involved in antigen processing and presentation, as well as increased Gag expression. This combined replication-competent NYVAC is a promising candidate for the next generation of HIV vaccines.
| S-EPMC3039654 | biostudies-literature
Project description:UnlabelledBecause sexual transmission of HIV occurs across mucosal membranes, understanding the immune responses of the genital mucosa to vaccines may contribute knowledge to finding an effective candidate HIV vaccine. We describe the uptake of rectal secretion, cervical secretion and seminal mucosal secretion sampling amongst volunteers in a Phase 1b HIV vaccine trial. Age at screening, gender, study site and the designation of the person conducting the informed consent procedure were collected for volunteers who screened for the HVTN 097 study. A total of 211 volunteers (54% female) were screened at three sites in South Africa: Soweto (n = 70, 33%), Cape Town (n = 68, 32%) and Klerksdorp (n = 73, 35%). Overall uptake of optional mucosal sampling amongst trial volunteers was 71% (n = 149). Compared to Cape Town, volunteers from Soweto and Klerksdorp were less likely to consent to sampling (Soweto OR 0.08 CI: 0.03-0.25 p<0.001 and Klerksdorp OR 0.13 CI: 0.04-0.41 p = 0.001). In contrast, volunteers over 25 years of age were 2.39 times more likely to consent than younger volunteers (CI: 1.13-5.08, p = 0.02). Further studies are required to better understand the cultural, demographic and sociobehavioral factors which influence willingness to participate in mucosal sampling in HIV prevention studies.Trial registrationClinicalTrials.gov: NCT02109354.
| S-EPMC4234370 | biostudies-literature