abstract
background
bacterial
cell
concept
corona
coronavirus
covid
covid19
danger
dangerous
disease
epidemic
fever
flu
global
h1n1
health
human
illness
infection
influenza
medical
medicine
mers
merscov
microbe
microbiology
organism
outbreak
outbreaking
pandemic
pneumonia
prevention
protect
protection
quarantine
sars
science
sick
sickness
vaccine
viral
virus
warning