Ключевые слова: bacteria, bacteriologist, bacteriology, biology, cell, contagiousness, covid, dangerous bacterium, disease, epidemic, epidemiology, health, infection, infectious threat, laboratory, medical diagnosis, medicine, microanalysis, microbial danger, microbiology, microbiota, microorganism, microorganisms, microscope, microscopic image, microworld, pandemic, pathogen, protection against viruses, science, treatment, viral attack, viral particle, virologist, virology, virus,