Study to Compare Safety and Immunogenicity of Commercial Scale Consistency Lots of Herpes Simplex Vaccine

Inclusion Criteria: * Healthy female between, and including, 10 and 17 years of age at the time of the first vaccination. * Seronegative for HSV-1 and HSV-2 at screening * Written informed assent obtained from the subject and written informed consent obtained from a parent or legal guardian of the subject prior to enrolment. If the subject is above the legal age of consent in her country, written informed consent will only be obtained from the subject. * Subject must have a negative urine pregnancy test. * Subject must be of non-childbearing potential, i.e. pre-menarcheal, or if of childbearing potential she must be abstinent or must be using an effective method of birth control for 30 days prior to vaccination, have a negative urine pregnancy test and must agree to continue such precautions for two months after completion of the vaccination series. Subjects who reach menarche during the study and therefore are of childbearing potential must agree to follow the same precautions. * A subject who (or whose parents/guardian) the investigator believes can and will comply with the requirements of the protocol Exclusion criteria: * Pregnant or lactating female. * Female planning to become pregnant during the first eight months of the study * Any previous history of, or current clinical signs or symptoms of oro-labial (cold sores), genital or non-genital HSV disease, such as swelling, papules, vesicles, pustules, ulcers, crusts, fissures, erythema, discharge, pain, burning, itching, tingling, or dysuria. * Previous vaccination against herpes. * History of erythema multiforme. * Use of any investigational or non-registered drug or vaccine other than the study vaccine(s) within 30 days preceding the first dose of study vaccine, or planned use during the study period. * Planned administration/administration of a non-study vaccine within 30 days before and after the first dose of study vaccine with the following exceptions: Administration of routine meningococcal, hepatitis B, inactivated influenza, diphtheria/tetanus and/or diphtheria/tetanus containing vaccine up to 8 days before the first dose of study vaccine is allowed. * History of allergic disease or reactions likely to be exacerbated by any component of the study vaccines * Any confirmed or suspected immunosuppressive or immunodeficient condition, including human immunodeficiency virus (HIV) infection. * History of a current acute or chronic autoimmune disease. * History of any neurologic disorders or seizures, with the exception of a single febrile seizure during childhood. * Acute or chronic, clinically significant pulmonary, cardiovascular, hepatic or renal functional abnormality, as determined by medical history or physical examination. * Acute disease at the time of enrolment * Oral temperature ≥99.5°F (\> 37.5°C) / axillary temperature ≥99.5°F (\> 37.5°C) at the time of enrolment * Chronic administration (defined as more than 14 days) of immunosuppressants or other immune-modifying drugs within six months prior to the first vaccine dose or planned use during the study period * Administration of immunoglobulins and/or any blood products within the three months preceding the first dose of study vaccine or planned administration during the study period.