Ключевые слова: 2019ncov, area, background, change, community, community immunity, concept, contagious, covid, covid19, crowded, cube, danger, epidemic, epidemiology, group, health, herd, herd effect, herd immunity, idea, illness, immunity, immunization, immunize, immunized, immunizing, lockdown, medical, outbreak, pandemic, population immunity, prevention, protection, protective, quarantine, sickness, spread, symbol, vaccinate, vaccinating, vaccination, vaccine, virus, white, word, zone,