MUCOBOOST trial

The DR230330 trial – ANRS0514s MUCOBOOST trial evaluates the safety and immunogenicity of a booster dose of an intranasal COVID-19 vaccine (LVT-001) compared to a booster dose of COVID-19 mRNA vaccine (Pfizer-BioNTech) in healthy adult volunteers.

Last updated on 02 December 2025

In brief

The DR230330 – ANRS0514s MUCOBOOST trial is a randomised, controlled, multicentre phase I/II trial, open-label trial comparing the safety and immunogenicity of a booster dose of an intranasal COVID-19 vaccine expressing recombinant SARS-CoV-2 N/S proteins with a booster dose of COVID-19 mRNA vaccine in healthy adult volunteers.

The randomised, comparative, multicentre, open-label, phase I/II MUCOBOOST trial was conducted in France on 36 and 202 healthy volunteers, enrolled in phase I and phase II respectively, with a 12-month follow-up period. It evaluates the safety and immunogenicity of a booster dose of an intranasal vaccine against COVID-19 (LVT-001) compared to a booster dose of an mRNA vaccine against COVID-19 (Pfizer-BioNTech).

Intervention

During Phase I, the investigational medicinal intranasal recombinant protein vaccine LVT-001 is administered on Day 1 (D0) in each nostril. Participants are divided into three cohorts, depending on the dose of the treatment:

  • Cohort A (12 participants): low dose
  • Cohort B (12 participants): medium dose
  • Cohort C (12 participants): high dose

During Phase II, two investigational drugs are being compared:

  • The selected dose of the LVT-001 intranasal recombinant protein vaccine, administered on Day 0 in each nostril
  • The intramuscular mRNA vaccine against COVID-19 (Pfizer-BioNTech), administered as a standard booster

Primary objectives

Phase I: To evaluate the safety of three different doses of a booster of an intranasal COVID-19 vaccine (LVT-001) expressing SARS-CoV-2 N/S recombinant protein in healthy volunteers.

Phase II: To evaluate, from nose swabs, the superiority of a booster dose of an intranasal COVID-19 vaccine (LVT-001) expressing SARS-CoV-2 N/S recombinant protein versus a booster dose of intramuscular COVID-19 mRNA vaccine (Pfizer-BioNTech) in healthy adult volunteers in terms of mucosal humoral immune response at D28.

Secondary objectives

  1. To evaluate, from nose swabs, the mucosal humoral immune response by measuring anti-S and anti-N IgA concentrations specific to the intranasal vaccine N/S recombinant proteins by ELISA at D0, D7 (Phase I), D14, D28 (Phase I), M3, M6 and M12, respectively in each arm.
  2. To evaluate, from nose swabs, the mucosal neutralizing immune response specific to the intranasal vaccine N/S recombinant proteins by PRNT and VLP assays at D0, D7 (Phase I), D14, D28, M3, M6 and M12, respectively in each arm.
  3. To evaluate, from serum samples, the systemic humoral immune response by measuring anti-S and anti-N IgG concentrations specific to the intranasal vaccine N/S recombinant proteins by ELISA at D0, D7 (Phase I), D14, D28, M3, M6 and M12, respectively in each arm.
  4. To evaluate, from serum samples, the systemic humoral neutralizing immune response specific to the intranasal vaccine N/S recombinant proteins by PRNT and VLP assays at D0, D7 (phase I), D14, D28, M3, M6 and M12, respectively in each arm.
  5. To evaluate, from blood samples, the systemic cellular immune response against N and S antigens by measuring the number of specific IFN--secreting T lymphocytes using the ELISpot technique at D0, D7 (Phase I), D14, D28, M3, M6 and M12 in each arm (subset of trial participants recruited in Tours center only).
  6. To evaluate the proportion of participants with confirmed COVID-19 infections in each arm between D0 and M12.
  7. To identify the variants of the SARS-CoV-2 virus that escape vaccination.
  8. To evaluate the proportion of participants with serious COVID-19 infections in each arm between D0 and M12.
  9. For Phase II only: To evaluate the safety and tolerability of the LVT-001 vaccine

What are the expected results?

In this Phase I trial involving healthy participants, no direct benefit is expected from trial participation, apart from the theoretical benefit of eliciting mucosal immune response against SARS-CoV-2. There are currently no data from clinical trials on the use of a nasal protein vaccine in humans. The expected risks include local nasal reactions as well as systemic reactions similar to those observed with other vaccines. Anticipated adverse events following vaccination should be manageable using standard routine care, as determined by the investigators. Therefore, the safety profile of this candidate vaccine supports the initiation of this Phase I/II clinical trial. Although this is the first time a nasal protein vaccine has been used in a human clinical trial, it will be administered in increasing doses, with built-in safety margins ensuring that progression to the next group of participants at the same dose is justified.

Status
Ongoing

Pathology
COVID-19

Number of participants
238

Sponsor
Inserm, ANRS MIE and CHRU de Tours

Funding
RECH MIE 2022 call for projects

Download the study information for researchers

.pdf 281 KB

Download the study information for participants

.pdf 63 KB

You are participating or have participated in this study

The above sheet contains information on ancillary studies for which your data/samples will be or may have been reused if you consented to this at the time of your inclusion.

If you would like to know more about your participation in a clinical study, please see the section below.

Visit the participant area