HPV-16 has been strongly implicated in the aetiology of cervical cancer and pre-malignant cervical intraepithelial neoplasia. Despite current technical difficulties it may soon be possible to treat these tumours with anti-HPV-16 vaccines. A prophylactic vaccine could, in theory, be developed to induce neutralizing antibodies to HPV-16 virions in genital secretions, and a therapeutic vaccine to elicit cytotoxic T-cell responses against established lesions.