An Experimental Medicine Multicenter Trial to Evaluate the Safety and Immunogenicity of Experimental Versus Authorized SARS-CoV-2 Vaccine Candidates as a Booster Dose in Healthy Participants Previously Vaccinated With Authorized mRNA SARS-CoV-2 Vaccines.

NCT07605520 | Recruiting Early Phase 1 DMC

• 1 other identifier: ANRS0711s SOLVE-01
• Study Type: interventional
• Target: 48
• Locations: 2 countries
• Sites: 3

Brief Summary

The SOLVE-01 trial is a study evaluating four SARS-CoV-2 vaccines as booster injections: two experimental vaccines (CD40.RBDv and CD40.Pan.CoV, both combined with the Hiltonol® adjuvant) and two authorised vaccines (Comirnaty® and NuvaxovidTM). This trial is designed for healthy adults aged 18 to 65 at the time of signing the informed consent form. The main objectives of this trial are:

• to evaluate the safety of the two experimental vaccines,
• to determine the antibody response induced by the vaccines and its durability. Participants will:
• Receive one injection of vaccine and two intradermal skin tests
• Come to the hospital 10 visits for medical exams and blood and saliva sample collection
• Keep a diary of their symptoms and the treatments taken

Conditions

Healthy Adults

Keywords

COVID19 vaccine; phase 1; experimental medicine trial

Outcome Measures

Primary Outcomes (2)

• Safety_Proportion of participants without any grade 3 or 4 adverse event

  Proportion of participants without any grade 3 or 4 solicited local/systemic or unsolicited AEs between Day 0 and Week 4 and considered to be related or possibly related to IMP administration

  Between Day 0 and Week 4

• Immunogenicity_Geometric mean titers of neutralizing antibodies

  Geometric mean titers of neutralizing antibodies against the original strain D614G and the relevant circulating variants measured at Week 4 and Week 48

  At Week 4 and Week 48

Secondary Outcomes (20)

• Safety_Number of Solicited local and systemic Adverse Reactions

  up to Day 7 (7 days post vaccination) for local ARs and Week 2 (14 days post vaccination) for systemic ARs

• Safety_Number of Unsolicited adverse events

  from Day 0 to end of trial

• Safety_Number of Serious Adverse Events

  from Day 0 to end of the trial

• Immunogenicity_humoral immune response (IgG binding)

  at Day 0 (before vaccination), Day 7, Week 2, Week 4, Week 12, Week 24, Week 36 and Week 48

• Immunogenicity_humoral immune response (IgG binding)

  at Day 0 (before vaccination), Day 7, Week 2, Week 4, Week 12, Week 24, Week 36 and Week 48

Study Arms (4)

CD40.RBDv/Hiltonol

EXPERIMENTAL

CD40.RBDv vaccine adjuvanted with Poly-ICLC (Hiltonol)

Biological: CD40.RBDv vaccine adjuvanted with Hiltonol®

CD40.Pan.CoV/Hiltonol

EXPERIMENTAL

CD40.Pan.CoV vaccine adjuvanted with Poly-ICLC (Hiltonol)

Biological: CD40.Pan.CoV vaccine adjuvanted with Hiltonol®

Comirnaty

ACTIVE COMPARATOR

Biological: Comirnaty® vaccine

Nuvaxovid

ACTIVE COMPARATOR

Biological: Nuvaxovid™ vaccine

Interventions

CD40.RBDv vaccine adjuvanted with Hiltonol® BIOLOGICAL

used at the dose of 1.0 mg subcutaneously Poly-ICLC adjuvant (Hiltonol) used at a dose of 1.0 mg and will be mixed with CD40.RBDv vaccine just prior to subcutaneous injection at day 0.

CD40.RBDv/Hiltonol

CD40.Pan.CoV vaccine adjuvanted with Hiltonol® BIOLOGICAL

used at the dose of 1.0 mg subcutaneously Poly-ICLC adjuvant (Hiltonol) used at a dose of 1.0 mg and will be mixed with CD40.Pan.CoV vaccine just prior to subcutaneous injection at day 0.

CD40.Pan.CoV/Hiltonol

Comirnaty® vaccine BIOLOGICAL

administered intramuscularly at day 0. The version of the Comirnaty® vaccine and the dose will be the one adapted to the variant circulating at the start of trial and authorised by EMA.

Comirnaty

Nuvaxovid™ vaccine BIOLOGICAL

administered intramuscularly at day 0. The version of the Nuvaxovid™ vaccine and the dose will be the one commercialised at the start of trial and authorised by EMA.

Nuvaxovid

Eligibility Criteria

• Age: 18 Years - 65 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Male and female subjects aged 18 to 65 years inclusive at the time of the screening visit
• Having received at least two doses of COVID-19 mRNA vaccines in the past with the last dose received more than 6 months prior to IMP administration in the trial
• In healthy condition or with stable health status which is defined as an existing disease that has not required a significant change in treatment or hospitalization for worsening before enrolment, and for which neither a significant change in treatment or hospitalization for worsening is expected in the near future.
• For woman of childbearing potential: a negative Beta-HCG blood test measure during the screening visit, and a negative highly sensitive pregnancy urinary test the day of the vaccination visit
• if heterosexually active female, consistently using a highly effective method of contraception with partner from at least 21 days prior to enrolment through 4 months after the IMP administration. Highly effective contraception is defined as using any of the following methods:
• Combined hormonal contraception with inhibition of ovulation (estrogen and progesterone containing);
• Intrauterine device (IUD);
• Intrauterine hormone releasing system (IUS);
• Hormonal contraception (progesterone only);
• Successful vasectomy in the male partner (considered successful if a participant reports that a male partner has (i) documentation of azoospermia by microscopy, or (ii) a vasectomy more than 2 years ago with no resultant pregnancy despite unprotected sexual activity post vasectomy);
• Or not be of reproductive potential, such as having reached menopause (no menses for 1 year without an alternative medical cause) or having undergone hysterectomy, bilateral oophorectomy, or tubal ligation.
• Agree not to seek pregnancy including through alternative methods, such as artificial insemination or in vitro fertilization until 4 months after the IMP administration.
• Participant who was born male, if heterosexually active male, using an effective method of contraception with their partner from the IMP administration until 4 months thereafter. All male participants also agree not to donate sperm during this period.
• Negative nasopharyngeal antigenic test for SARS-CoV-2 on the day of screening and before randomisation
• Participant who has normal biological values:

You may not qualify if:

• Any medical condition that could impair the immune response: clinically significant medical condition, physical examination findings, clinically significant abnormal laboratory results, or past medical history with clinically significant implications for current health. A clinically significant condition or process includes but is not limited to:
• A process that would affect the immune response;
• A process that would require medication that affects the immune response;
• Any contraindication to repeated injections or blood draws;
• A condition that requires active medical intervention or monitoring to avert grave danger to the participant's health or well-being during the study period;
• A condition or process for which signs or symptoms could be confused with reactions to vaccine, or
• Pregnancy or breastfeeding that is currently ongoing, or positive pregnancy test at screening visit and the day of the vaccination
• Immunodeficiency
• Asthma: a condition that requires active medical intervention or monitoring to avert grave danger to asthma other than mild, well-controlled asthma. (Symptoms of asthma severity as defined in the most recent National Asthma Education and Prevention Program (NAEPP) Expert Panel report). Exclude a participant who:
• Uses a short-acting rescue inhaler (typically a beta 2 agonist) daily, or
• Uses moderate/high dose inhaled corticosteroids, or
• In the past year has either of the following: (i) Greater than 1 exacerbation of symptoms treated with oral/parenteral corticosteroids or (ii) Needed emergency care, urgent care, hospitalization, or intubation for asthma.
• Diabetes type 1 or type 2, including cases controlled with diet alone. (Not excluded: history of isolated gestational diabetes).
• Thyroidectomy, or thyroid disease requiring medication during the last 12 months
• Hypertension:

Sponsors & Collaborators

• ANRS, Emerging Infectious Diseases: lead

Study Sites (3)

Hôpital Henri Mondor

Créteil, France

RECRUITING

CIC 1417 - Hôpital Cochin

Paris, France

RECRUITING

Centre Hospitalier Universitaire Vaudois (CHUV)

Lausanne, Switzerland

RECRUITING

MeSH Terms

Interventions

poly ICLC

Central Study Contacts

Yves LEVY, Pr

CONTACT

+33(0)149814442; yves.levy@aphp.fr

Giuseppe PANTALEO, Pr

CONTACT

+41(0)213141063; Giuseppe.Pantaleo@chuv.ch

Study Design

• Study Type: interventional
• Phase: early phase 1
• Allocation: RANDOMIZED
• Masking: NONE
• Purpose: TREATMENT
• Intervention Model: PARALLEL
• Sponsor Type: OTHER GOV
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: May 7, 2026
• First Posted: May 26, 2026
• Study Start: May 13, 2026
• Primary Completion (Estimated): May 1, 2028
• Study Completion (Estimated): December 1, 2028
• Last Updated: June 2, 2026

Record last verified: 2026-06

Locations

FR (2); CH (1)