influenza (flu) virus on the nasal mucosa lines - closeup view 3d

influenza infection viral covid-19 vaccine flu type iav ibv nasal mucosa lines contagious cough pain fatigue runny nose sore throat diarrhea vomiting aches muscle disease sickness lung ill sick illness fever catarrh symptom dejected respiratory epihtelium air-filled spaces respiration cavity mucosa mucous membrane tract receptor dust snoke pollen thermometer epidemics h1n1 h3n2 pcr viral nucleic acid