Patient

http://www.flickr.com/photos/tukatuka/3636160788/

Vaccine

http://www.flickr.com/photos/doug88888

Sickness

http://www.flickr.com/photos/tranchis/4185292603

Vector

http://www.flickr.com/photos/trekman/2319701434

Fungi

http://www.flickr.com/photos/selva/9263208

http://www.flickr.com/photos/catikaoe/2639277121

Fever

http://www.flickr.com/photos/yersinia/4440378237

Cells

Pills

http://www.flickr.com/photos/eagleglide/3077556441

Graveyard

http://www.flickr.com/photos/zachstern/2349408400

Quarantine

http://www.flickr.com/photos/meredithfarmer/314004290/