Inclusion Criteria:

• 18 years of age and over at the time of first vaccination
• Written informed consent
• Females of childbearing potential must have a negative pregnancy test at enrollment and prior to each vaccination and be using an accepted method of birth control

Exclusion Criteria:

• Any previous history of or current clinical signs or symptoms of genital herpes disease.
• Any previous vaccination against herpes simplex.
• Any previous administration of MPL.
• History of herpetic keratitis.
• History of erythema multiforme.
• Female subjects who are pregnant, lactating or planning a pregnancy before one month after the last vaccine dose
• Patient is immuno-compromised or is receiving immuno-modifying therapy of any kind. Topical corticoid therapy is allowed.
• HIV positive at the time of enrollment
• Clinical signs of acute or febrile illness at the time of entry into the study.
• Any continuous suppressive antiviral oral therapy within the 6 months prior to entry.
• Any administration of immunoglobulins during the vaccination course or within one month prior to the first vaccination.
• Any vaccine administration less than one week before or after a study vaccination.
• Previous known hypersensitivity to vaccination or to any component of the vaccine.
• Simultaneous participation in any other clinical trial of an investigational drug or vaccine concurrent with this study or during the period beginning 30 days prior to entry into the study or 5 half-lives of the drug
• Recent history of alcoholism or drug abuse
• Recent clinical history or evidence of significant hepatic disease
• History of a current acute or chronic auto immune disease.
• Recent clinical history or evidence of renal dysfunction
• Life-threatening or serious cardiac (NYHA grades III-IV), gastrointestinal, haematological or immunological disorder which, in the opinion of the investigator, would preclude entry into the study.
• Inability or unwillingness to comply with the protocol or not expected to complete the study period