Observational Program, Study the Preventive Efficacy of the BiVac Polio Vaccine Against the Incidence of Acute Respiratory Infections, Including COVID-19

Inclusion Criteria: * Volunteers must meet the following inclusion criteria: * Healthy volunteers aged 18-65 years. * The presence of a written and dated informed consent of the volunteer to participate in the program. * Consent to observe precautionary measures to limit the circulation of the vaccine virus among people around the vaccinated person (personal hygiene, isolation from unvaccinated children and people with immunodeficiency). * Volunteers who are able to fulfill the requirements of the protocol (i.e., fill out a self-observation diary, remember the dates of control visit). Non-inclusion criteria: * COVID-19 infection (including cases of asymptomatic carrier). * Positive test for COVID-19 (PCR). * Vaccination with any live and / or replicative vaccine one month before screening. * Neurological disorders that accompany previous vaccination with oral polio vaccine. * Immunodeficiency condition (primary). * Malignant neoplasms. * Immunosuppression (vaccinations are carried out no earlier than 3 months after the end of the course of therapy). * Pregnancy. * Hypersensitivity to any component of the vaccine. * Strong reaction (temperature above 40°C) or a complication on the previous administration of the drug. * Acute infectious or non-infectious diseases. Vaccinations are carried out 2-4 weeks after recovery or remission. In case of mild acute respiratory viral infections, acute intestinal diseases, vaccinations are carried out after the temperature normalizes. * The presence in the family or immediate environment (and provided that it is impossible to separate) of unvaccinated against polio (for example, newborns or children who have contraindications to polio vaccinations). * The presence of persons with immunodeficiency in the family or immediate environment (and provided that it is impossible to separate). Exclusion Criteria: * A volunteer can be excluded from the study under the following conditions: * Refusal of a volunteer to participate in the program. * The need for procedures and / or drug treatment that are not permitted by the protocol of this study. * The volunteer was included in violation of the inclusion/non-inclusion criteria of the Protocol. * The appearance of non-inclusion criteria during the study. * Non-compliance with the research procedures by the volunteer. • Any condition of the volunteer that requires, in the reasonable opinion of the research doctor, the withdrawal of the volunteer from the study. * The volunteer is out of observation. • For administrative reasons