Ключевые слова: alert, banner, biohazard, community, concept, disease, distance, flu, health, herd, herd effect, herd immunity, ill, illness, immune, immune system, immunity, immunization, infected, infection, influenza, medical, medicine, microorganism, pandemic, pathogens, people, prevention, preventive, protection, quarantine, science, sick, sign, social, spread, symbol, treatment, vaccination, vaccine, virus,