The goals of this clinical trial are: 1. Phase 2: to test a gamma adapted recombinant vaccine against SARS-CoV-2 in healthy adult volunteers, previously vaccinated against the SARS-CoV-2 virus. 2. Phase 3 (first volunteer enrollement on March 25, 2023): to test a recombinant vaccine against SARS-CoV-2 comparing three different versions (Gamma Variant RBD-based ARVAC-CG vaccine, Omicron Variant RBD-based ARVAC-CG vaccine, Bivariant Gamma/Omicron RBD-based ARVAC-CG vaccine), in adult volunteers previously vaccinated against the SARS-CoV-2 virus The main questions to be answered are: 1. Phase 2: 1. What si the immune response after one dose of vaccine? 2. What is the safety and tolerability profile of this vaccine? 2. Phase 3 : 1. What is the immune response triggered by each vaccine formulation against Wuhan, gamma, and omicron variants. 2. What is the safety and tolerability profile of this vaccine? In phase 2, participants will receive one dose of the study vaccine and one dose of placebo 28 days apart, in a cross-over design. In phase 3 (not yet recruitment), participants will be randomized to receive one of the three possible types of vaccines and all of them will receive one dose of the corresponding vaccine and 1 dose of placebo 28 days apart, in a cross over design.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
PREVENTION
Masking
QUADRUPLE
Enrollment
2,014
Vaccine containing 50 µg of antigen + Alum. Schedule: One booster dose of vaccine Administration route: intramuscular (IM) injection
Vaccine containing 50 µg of antigen + Alum. Schedule: One booster dose of vaccine Administration route: intramuscular (IM) injection
Vaccine containing 25 µg of gamma antigen + 25 µg of omicron antigen + Alum Schedule: One booster dose of vaccine Administration route: intramuscular (IM) injection
Schedule: One dose of placebo in a crossover design Administration route: intramuscular (IM) injection
Fundación Huesped
Buenos Aires, Buenos Aires F.D., Argentina
Centro de Investigaciones Clínicas Belgrano (CICB)
Buenos Aires, Buenos Aires F.D., Argentina
Centro de Educación Médica e Investigaciones Clínicas "Norberto Quirno" - CEMIC
Argentina, C.a.b.a., Argentina
Clinica Privada del Sol
Córdoba, Córdoba Province, Argentina
FP Clinical Pharma
Buenos Aires, Argentina
Vacunar S.A.
Buenos Aires, Argentina
Instituto Medico Platense
Buenos Aires, Argentina
Instituto de Investigaciones Clínicas de Mar del Plata
Buenos Aires, Argentina
Centro Clínica del Niño y la Familia
Buenos Aires, Argentina
Centro Médico Dra. Laura Maffei - Investigación Clínica Aplicada
Ciudad de Buenos Aires, Argentina
...and 1 more locations
Phase 2 - Immunogenicity - Seroconvertion rate
Seroconversion rate defined by a 4-fold increase from baseline of neutralizing antibody titer
Time frame: 14 days after vaccination
Phase 3 - Immunogenicity - Seroconvertion rate
Seroconversion rate defined by a 4-fold increase from baseline of neutralizing antibody titer comparing the different arms
Time frame: 14 days after vaccination
Immunogenicity - Neutralizing antibody titer
Proportion of individuals whith at least 8-fold increase from baseline
Time frame: 14 days after vaccination
Immunogenicity - Neutralizing and total antibody titers
Geometric Mean Titer (GMT)
Time frame: At baseline, 14 and 90 days after vaccination
Safety - Solicited local and systemic reactions after vaccination
Number of volunteers overall and in each vaccination group with local or systemic vaccine reactogenicity, based on evaluacion of solicited adverse events (AEs) recorded on subject memory aids o during clinical assessments
Time frame: Day 0 to 7 days after vaccination
Safety - Unsolicited adverse events after vaccination
Number of volunteers overall and in each vaccination group
Time frame: Day 0 to 30 days after vaccination
Safety - Serious Adverse Events
Number of volunteers overall and in each vaccination group with vaccine associated serioius adverse events (SAEs)
Time frame: Day 0 to 30 days after vaccination
Safety - Variations in laboratory results
Number of volunteers overall and in each vaccination group with variations in laboratory results from a baseline control
Time frame: At 30 days after vaccination
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