Ключевые слова: allergy, background, bacteria, care, clinical, corona virus, covid 2019, disease, doctor, epidemic, female, filter, grippe, health, health care, help, hospital, human, hygiene, infected, infection, influenza, man, mask, medic, medical, medicine, medicine mask, mouth, nurse, pandemic, person, prevention, protection, protective mask, protects, smog, stethoscope, surgeon, surgery, symptom, toxic, treatments, uniform, urban, vaccine, virus, wuhan, young,