A major international trial has confirmed the effectiveness of a cervical cancer vaccine developed in Australia. The vaccine was created by Professor Ian Frazer, who is from Brisbane's Centre for Immunology and Cancer Research. Trials on 12,000 women from 13 countries, which have been sponsored by US drug company Merck, show the treatment is 100 per cent effective in preventing the most common form of cervical cancer. The vaccine works by blocking two strains of the sexually transmitted human papilloma virus (HPV), which causes up to 70 per cent of cervical cancers. Dr Eliav Barr, from Merck research laboratories, says more than 50 per cent of women will become infected with HPV at some point during their lives. "Not all HPV infections are dangerous, most go away by itself," he said.