2019
alertness
attention
bacteria
bacterium
biohazard symbol
caution
corona
coronavirus
danger
dangerous
dangerous virus
dead
epidemic
fever
flu virus
hazard sign
hazardous area sign
health
hospital
illness
illustration
infection
infectious disease
influenza
isolated
medical
medicine
microbe
microbiology
outbreak
pneumonia
protection
quarantine
respiratory
risk
safety
science
sickness
stop sign
treatment
vaccination
virus
warning sign
warning symbol