Study to Evaluate the Ability of Sublingual MV130 to Induce the Expression of Trained Immunity in Peripheral Blood Cells

A mechanistic clinical trial with the aim to evaluate whether MV130 can induce the expression of a particular immune response (trained immunity) in peripheral blood cells. Therefore, the investigators are not evaluating efficacy in any disease or medical condition but rather assessing the immunological effect in immunogenicity of MV130 in healthy volunteers.

Bacillus Calmette-Guérin (BCG) has been postulated as a strategy to prevent transmission and reduce the incidence of infectious diseases due to its ability to induce trained immunity. However, it is not recommended to vaccinate with live-attenuated vaccines, such as BCG, to certain vulnerable populations including immunocompromised patients. This issue can be overcome with inactivated preparations that mediate trained immunity such as MV130. The safety of MV130 in pilot studies in patients with immunodeficiency or solid organ recipients, has been highlighted in recent studies.

Based on the principles of trained immunity, it has recently been suggested that this concept can be further exploited in a next generation of anti-infectious vaccines: Trained immunity-based vaccines (TIbV). Thus, these vaccines may confer a broad protection far beyond to the nominal antigens they contain.

Eligibility Criteria:
Inclusion Criteria:

* Subjects that have provided written informed consent.
* Healthy males and females 18 to 65 years, both included, at the time of enrolment.
* Subjects who are able to provide cooperation and comply with dosing regimen.
* Women of childbearing age (from menarche) should submit a urine pregnancy test with a negative result at the time of enrolment in the trial.

Exclusion Criteria:

* Simultaneous participation in another clinical trial.
* Females who are pregnant or breast-feeding, or potential pregnant or breast-feeding females.
* Subjects who are allergic to any of the components included in MV130.
* Subjects with any concomitant disease or treatment that, according to the investigator criteria, may affect the development of this study, such as immunodeficiencies, malignancies involving bone marrow or lymphoid systems, medical treatment affecting the immune system (including corticosteroids, immunosuppressants, biological agents,...), human immunodeficiency virus, severe allergies, diabetes, hypertension, psychological disorders, etc.
* Subjects who have been vaccinated within 12 months before inclusion (flu or any other vaccine different from COVID-19 vaccine), or who have planned to be vaccinated during the clinical study (excluding the COVID-19 vaccine).
* Subjects who have had an infection that included fever and/or diarrhoea within 3 months before inclusion.
* Subjects under metformin treatment during the last month before inclusion in the clinical study or during the clinical trial\*.
* Subjects under statins treatment during the last month before inclusion in the clinical trial or during\*.

  \*: these drugs interfere with metabolic pathways involved in trained immunity induction.
* Subjects who are allergic to any of the components included in the flu vaccine.