This trial aims to test the safety of 2 doses of a T-cell priming specific cocktail of Dengue viruses peptides representing all 4 DENV serotypes and mounted on a gold nanoparticle. NOTE: This is the master protocol of a prospective 2-stage adaptive trial, which aims to add and test a Coronavirus vaccine candidate as well, in an identical trial design.
A critical limitation for Dengue vaccines is their association with antibody-dependent enhancement, where poorly formed immune responses predispose the individual to severe disease during a second infection. Thus, a more targeted vaccine (inducing / priming T cells and not producing antibodies) could be the best alternative and most successful preventive method in the fight against severe manifestations of the disease. Nanoparticle antigen delivery systems have been developed to enrich specific targeting of immune receptors. These carrier systems are designed to facilitate antigen uptake and processing by antigen presenting cells (APCs), as well as to control antigen release and protect them from premature proteolytic degradation. This more targeted response also allows us to reduce the effective antigen dose (to nanomoles) and mimic a replicating infection with zero risk of developing the infectious disease. The hypotheses are listed below: 1. During the COVID-19 pandemic, Dengue virus disease is likely to cause significant diagnostic confusion and it risks further progression due to disrupted control measures. 2. As the SARS-CoV-2 pandemic devastates the world, the need for highly efficient and scalable vaccines is desperately required. 3. Peptide vaccines have high potential as a rapidly scalable modular platform for emerging diseases requiring targeted immunological responses. 4. Dengue viruses and Coronaviruses (e.g. COVID-19 causing viruses) are particularly well suited to this approach. For this initial naNO-DENGUE part of the trial, the objectives are as follows: Primary: To evaluate the safety and reactogenicity of two intradermal injections of two different doses of the investigational Dengue peptide T cell inducing vaccine (PepGNP-Dengue) administered to healthy volunteers as a: 1. candidate vaccine for the prevention of Dengue 2. proof-of-concept for a rapidly scalable modular peptide vaccine platform, which will be followed by a COVID-19 construct after interim analyses. Secondary: 1. To assess the evidence of a T-cell mediated immune response as a surrogate of protection against severe dengue disease using a novel peptide set-point vaccine in healthy adults. 2. To check the absence of an antibody mediated response For naNO-DENGUE, a total of 26 eligible participants will be randomized into the following groups: * Group 1 (n=13): 10 Low Dose (LD) PepGNP-Dengue (2.5 nmol) + 3 Comparator * Group 2 (n=13): 10 High Dose (HD) PepGNP-Dengue (7.5 nmol) + 3 Comparator, Thus, 20/26 vaccine vera and 6/26 Comparator controls. Allocations of vaccine vera vs Comparator for each group are double-blinded. Each arm will be staggered into a "Pioneer" group (3/13 participants) followed a week later after a safety review by the remaining 10/13 "Followers". This is the master protocol for a 2-stage study investigating the safety of 2 vaccines from a T Cell priming vaccine platform for emerging diseases: Stage 1: naNO-DENGUE A Phase-I study of a nanoparticle-based peptide vaccine against Dengue (Master protocol) Stage 2: naNO-COVID A Phase-I study of a nanoparticle-based peptide vaccine against SARS-CoV2 (Sub-protocol)
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
PREVENTION
Masking
QUADRUPLE
Enrollment
26
Two intradermal injections in the upper arm spaced 21 days apart
Two intradermal injections in the upper arm spaced 21 days apart
Two intradermal injections in the upper arm spaced 21 days apart
Center for Primary Care and Public Health, (Unisante)
Lausanne, Canton of Vaud, Switzerland
Safety: Solicited local & Systemic AEs
Number of volunteers overall and in each dose group with local or systemic vaccine reactogenicity, based on evaluation of solicited adverse events (AEs) recorded on subject memory aids or during clinical assessments
Time frame: Through 14 days after prime or boost vaccination
Safety: Unsolicited AEs
Number of volunteers overall and in each dose group with unsolicited vaccine-associated adverse events (AEs) in each dose group
Time frame: Study Days 0-180 or through termination visit, if terminated early
Safety: SAEs
Number of volunteers overall and in each dose group with vaccine-associated serious adverse events (SAEs)
Time frame: Study Days 0-180 or through termination visit, if terminated early
Safety: Adverse Events of Special Interest (AESI)
Number of volunteers overall and in each dose group with vaccine-associated adverse events of special interest (AESIs)
Time frame: Study Days 0-180 or through termination visit, if terminated early
Safety: Haemoglobin blood levels measurement
Number of volunteers overall and in each dose group with abnormal results in blood test regarding haemoglobin (Hb) measured in g/l. Reference range (from "Toxicity Grading Scale for Healthy Adult and Adolescent Volunteers Enrolled in Preventive Vaccine Clinical Trials" - https://www.fda.gov/media/73679/download): Female 117-157 g/l / Male: 133-177 g/l) Anaemia reported as: GRADE 1: \<117 - 100 g/l GRADE 2: \<100 - 80 g/l GRADE 3: \< 80 g/l
Time frame: Screening, Days 7, 14, 28, 35
Safety: Alkaline Phosphate Blood levels measurement
Number of volunteers overall and in each dose group with abnormal results in blood test regarding Alkaline phosphate measured in U/L. Reference ranges (from "Toxicity Grading Scale for Healthy Adult and Adolescent Volunteers Enrolled in Preventive Vaccine Clinical Trials" - https://www.fda.gov/media/73679/download): 36-120 U/L Elevation in Alkaline phosphate reported as: GRADE 1: 121 - 300 U/L GRADE 2: \>300 - 600 U/L GRADE 3: \>600 U/L
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Two intradermal injections in the upper arm spaced 21 days apart
Time frame: Screening, Days 7, 14, 28, 35
Immunogenicity: Proportion of participants with CD8-T cell specific to PepGNP-Dengue
Frequency of CD8+ T cells specific peptides by cytometry ex vivo, using staining with dengue specific dextramers and activation-induced markers (AIM)
Time frame: Study Days 0-180 or through termination visit, if terminated early
Proportion of participants becoming seropositive (antibodies against Dengue virus)
Dengue serology rapid test: Serology to detect antibodies against the four dengue serotypes by rapid test Anti-DENV2 Ig: Serology to detect antibodies against natural DENV (lysate or inactivated viral particles), by ELISA
Time frame: Study Days 0-180 or through termination visit, if terminated early