Vector

http://farm4.staticflickr.com/3149/2783124139_7374c77b49_z.jpg?zz=1

Hospital

http://s0.geograph.org.uk/photos/02/10/021092_3c4ac3df.jpg

Pathogen

http://farm6.staticflickr.com/5227/5634409581_2ff37c93a7_b.jpg

Antibiotics

http://farm1.staticflickr.com/53/117311111_eb5ddb0fe4_b.jpg

http://farm6.staticflickr.com/5292/5448956846_4caab80e41_b.jpg

Vaccine

Cell

http://farm3.staticflickr.com/2701/4262788973_828d82b404_o.jpg

Fungi

http://farm5.staticflickr.com/4086/4834802500_f6f7cc1b8d_b.jpg

Doctor

http://farm3.staticflickr.com/2448/3782138498_db122010d9_b.jpg

AIDS

http://farm1.staticflickr.com/137/348295375_817efdcaf3_z.jpg

Contagion

http://farm3.staticflickr.com/2121/2062522813_c5d0fe341b_b.jpg