Introduction: The SARS Co-2 contagious rate is high (Ro: 2.0-3.0). The infection is aggressive with high pathogenicity. Global confinement impacts all social and economic fields of human activity. Clinical behavior exceeds the capabilities of public health care. With the initial information on the pandemic, it is estimated that 20% of health personnel in direct contact with patients can acquire the disease, despite preventive self-care. The molecular relationship of COVID-19 with the subject's ACE2 protein encourages the virus to enter the host cell, and initiates replication and the immune response, causing an imbalance generating an immunological storm of cytokines, with serious damage to the host.

Objective: It is proposed to supply a combined scheme of two compounds by oropharyngeal spray that captures the virus before entering the target cell and orally administer immunomodulatory compounds that regulate the inflammatory response released by the virus, in order to improve the antiviral response.

Methodology: A controlled, parallel design, triple-blind, phase II clinical trial will be conducted with two study groups to compare the active compounds (oropharyngeal spray and emulsion) with placebo.

Discussion: With the application of the combined scheme of two compounds, a 75% reduction in infection is expected for workers in direct contact with COVID patients.

RESEARCH QUESTION: Can the oropharyngeal spray of a viral blocking compound in conjunction with the provision of an immunostimulant emulsion, reduce the infection proportion by 2/3

ACTIVE PRINCIPLE Intervention 1. BlockACE2® spray, antimicrobial and antiviral liquid solution for mouth spray, composed of 3 natural bioactive substances proven to be used in humans, which present molecular structures homologous to the native receptor of the virus. It contains binding peptides that resemble the ACE2 receptor, which bind to viral fractions, and acts as soluble scavengers of the virus at the entrance gate, upper respiratory tract, or oropharyngeal region, preventing its entry into the target cell and decreasing the amount of virus that enters the body; consequently, they reduce their ability to generate damage.

BlockACE2® Defense, food for oral administration in the form of an emulsion with 8 bioactive components that have shown modulation of the inflammatory response. Contains natural oils, Vitamin B6, Vitamin C, Vitamin E, Vitamin D3 100 SD / S, and minerals; key micronutrients that are not normally obtained through a traditional diet. These nutrients are immunostimulants with proven capacity to enhance the cellular response against viruses, anti-inflammatory, antioxidant, and chemoprotective activity, stimulating the production of interferon I; and as a whole, they prevent the generation of an excessive immune activation process, known as an "immune storm" mediated by pro-inflammatory cytokines.

Intervention 2, Placebo:

Preparations without active components in the pharmaceutical form of the above (Intervention 1 and Intervention 2). They will be presented with the same physical characteristics such as size, shape, color, taste, smell, consistency, printed signs, weight, surface finish, internal and external; in order to guarantee the principle of masking.

RESEARCH HYPOTHESIS:

In a population with community risk of COVID-19 infection, the combined use of the study interventions (the oral antimicrobial solution in Spray BlockACE2® and the food in BlockACE2® emulsion, compared to the use of Placebo, reduces the risk of COVID-19 infection expressed in a negative PCR result in those who seroconvert to IgM, and in those who seroconvert, the higher proportion will be in the mild-moderate clinical form.

PRIMARY OBJECTIVE To establish the efficacy of the combined use of BlockACE2® oropharyngeal spray, and BlockACE2® emulsion, in comparison with placebo on the reduction of the risk of infection by COVID-19, expressed in the negative result of immunoglobulins for COVID-19 (30 days from admission to the project).

Establish the safety of the products under study by evaluating the expected and unexpected adverse events that are recorded during the use phase of the intervention scheme (30 days from project entry).

SECONDARY OBJECTIVE To establish the efficacy of the combined use of BlockACE2® spray, a soluble virus scavenger compound plus ingestion of BlockACE2® emulsion, a compound that improves the defenses of the immune system, compared to placebo, on reducing the risk of infection by COVID-19 expressed in the clinical response of the disease that is defined in three variables, mild to moderate: onset of fever, myalgia, and cough without dyspnea; severe: fever, myalgia, cough and dyspnea requiring hospital care; and critical: all the above plus ventilatory assistance in ICU.

EXPLORATORY OBJECTIVES Explore the efficacy of the combined use of BlockACE2® spray, a soluble virus scavenger compound, plus the intake of BlockACE2®, an emulsion food with key micronutrients that stimulate the antiviral cellular immune response on reducing the risk of COVID-19 infection expressed in the negative result of IgG, IgM; and the reduction of the risk of symptoms such as fever, cough, dyspnea, myalgia, or ventilatory assistance in the ICU after 15 days of finishing the scheme.

FIELD OF STUDY: Workers of every department of Conconcreto Company in the city of Medellín and Girardota

INTERVENTIONS:

Intervention 1 BLOCKACE2: Two oropharyngeal sprays of the compound, every 4 hours, during the day. For the BlockACE2 emulsion will be used 20 ml during the first 5 days and after it only 10ml every day for 30 days. Dosing of the substances in intervention 1 follows the described pharmacological characteristics, that guarantee its permanence in the oral mucosa to protect the entry pathway of the virus into the organism (Oropharynx). The dosage of the oral compounds was defined according to recommendations of the WHO for the modulation of the immune response (Emulsion).

Intervention 2 PLACEBO: spray and emulsion with similar color, smell, and texture but without the natural active compounds.

In the randomization visit V1, each participant will be assigned a treatment scheme, composed of intervention 1 and intervention 2, in sufficient quantity for the duration of the study. The pharmaceutical service will dispense the code of the scheme, following a sequential order, indicated in an allocation listing of the schemes on site. Each treatment scheme is labeled with a unique code that identifies it, and it contains One (1) device for oropharyngeal spray, with a capacity for 200 applications. One (1) bottle with 360 ml (oral). In the subsequent visits, the adherence to the dispensed schemes will be verified. The frequency of use will be checked, and dosing omissions will be registered by frequency (1 dose, once a week, more than once a week).

Inclusion Criteria:

1. Age between 18 and 60 years.
2. Health care worker in the front line of care of suspected or confirmed cases of COVID-19.
3. Negative IgM antibodies.

Exclusion Criteria:

1. Being a participant in another trial with another drug.
2. Temperature above 38ºC.
3. Having cohabited in the past 15 days with a person diagnosed with CoV-19.
4. Pregnancy.
5. Active o past smoker.
6. Known hypersensitivity to drugs or food.
7. History of respiratory disease.
8. Underlying diseases (Hypertension, cancer, diabetes, cardiovascular disease, leukopenia).
9. Signs or symptoms of CoV-19 infection: cough, dyspnea, myalgias.

Once the participant has given its informed consent, and the research team has verified the fulfillment of the inclusion criteria, the prospect receives a text message, to be directed to the pharmaceutical service. The numbered scheme will be dispensed with the code of the intervention, following the order from the allocation listing, provided by the CTCC. The head of the pharmaceutical service will register the date and time of the first dose. He will provide indications for the use, handling, and conservation of the products. Warning signs and symptoms and instructions for communication with the research team to address any concerns the subject may have will be reviewed. He will remind the subject to avoid its damage or loss. He will give the participant instructions to return the container and surpluses of the products at the end of the trial (day 30), he will point out that they are for personal use only and that they cannot be shared.