alert
awareness
background
bacteria
bacterium
biology
blood
cell
cells
corona
coronavirus
covid19
disease
epidemic
flu
global
globe
health
hospital
human
illness
illustration
infected
infection
influenza
lung
lungs sars
medical
medicine
microbiology
microscopic
pandemic
pathogen
pneumonia
recautions
respiratory
sars
severe
spread
symptoms
system
temperature
thermometer
treatment
virus
warning
world