Ключевые слова: alertness, backgrounds, bacterium, biological cell, biology, blood, blood test, closeup, cold and flu, covid19, danger, death, digitally generated image, epidemic, forbidden, healthcare and medicine, hepatitis, horizontal, illness, illustration, infectious disease, italy, laboratory, macrophotography, magnification, medicine, micro organism, microbiology, middle east respiratory syndrome, no people, organic, panoramic, pathogen, pneumonia, red, research, science, sign, sudden acute respiratory syndrome, test, test kit, three dimensional, trafficking, transportation, viral infection, virus, virus test,