Cervical cancer vaccine. Colour Transmission Elec- tron Micrograph of Vaccinia viruses genetically engineered into a vaccine against cervical cancer in women. This was developed at Johns Hopkins Medical Institutions, USA. Each year 200, 000 women worldwide die of cervical cancer. Over 90% of this cancer is associated with infection by Human Papilloma Virus (HPV); an E7 antigen in this virus turns normal cervical cells cancerous. The cancer then rapidly multiplies without being recognised by the immune system. The vaccine employs the Vaccinia virus to insert a molecular tag (LAMP-1) in affected cells to make E7 recognisable. This alerts the immune system to kill the cancer cells.