To study the level of the secretory component IgA of epithelial cells from the nasal mucosa, pharyngeal scraping and in secretions of salivary glands and the course of COVID-19 in patients with a combined regimen of intranasal (IN) and subcutaneous (SC) administration of the bacterial ligand based immunostimulant Immunovac VP4. Here, CD79A is linked to COVID-19.