anti
antiseptic
antiviral
bacteria
bacterium
biohazard
blue
care
cartoon
caution
clean
control
crossed
danger
dangerous
disease
flu
hazard
health
hospital
humor
hygiene
icon
illness
illustration
infected
infection
kill
medical
medicine
microbe
microbiology
monster
no
organism
parasite
protection
protest
quarantine
risk
safety
science
sign
sticker
stop
symbol
vaccination
virus
warning