Systems Biology of Zoster Vaccine (ZOSTAVAX®) in Young and Elderly

Inclusion Criteria: * Able to understand and give informed consent. * Immunocompetent subjects aged 25-40 years, or community dwelling subjects between the ages of 60-79. Exclusion Criteria: * Young adults aged 25-40 years who are Varicella-Zoster virus seronegative or equivocal results (mean value OD for Varicella-Zoster virus IgG lower than 1.1 by commercial enzyme-linked immunosorbent assay (ELISA) (Hope Clinic: IgG VZV ELISAII-Wampole Laboratories®, NJ, USA- Vaccine Research Trials Center:: Liaison VZV IgG Assay, DiaSorin, Italy) * Receipt of immune products: * Receipt of blood products within 6 months prior to vaccination with Zoster vaccine or expected receipt through 6 months after vaccination with Zoster vaccine\* * Receipt of any vaccine within 4 weeks prior to vaccination with Zoster vaccine or expected receipt within 4 weeks after vaccination with Zoster vaccine\* * Receipt of Zoster vaccine or varicella vaccines at any time prior to study entry. * Subject taking any non-topical antiviral therapy with activity against herpes viruses, including but not limited to acyclovir, famciclovir, valacyclovir, and ganciclovir 3 days prior to vaccination or 14 days after\*. * Prior history of shingles. * Presence of certain co morbidities or immunosuppressive states such as: * Chronic medical problems including (but not limited to) insulin-dependent diabetes, severe heart, lung, liver, or kidney diseases; auto immune diseases; severe gastrointestinal diseases; and uncontrolled hypertension. * Alcohol or drug abuse and psychiatric conditions that in the opinion of the investigator would preclude compliance with the trial or interpretation of safety or endpoint data. * Impaired immune function or chronic infections including (but not limited to) HIV, hepatitis B or C, tuberculosis, organ transplant, cancer, current and or expected receipt of chemotherapy, radiation therapy, steroids \[i.e., \> 20 mg of prednisone given daily or on alternative days for 2 weeks or more in the past 90 days\*); (nasal and topical steroids are allowed)\],antitumor necrosis factor agents, or any other immunosuppressive therapy, anatomic or functional asplenia, congenital immunodeficiency. * Pregnant or breast-feeding women, or women expecting to conceive 30 days before and 90 days after vaccination\*\*. * Conditions that could affect the safety of the volunteers such as: * Severe reactions to prior vaccinations. * History of anaphylactic/anaphylactoid reaction to gelatin, neomycin or any other component of the vaccine. Neomycin allergy manifested as contact dermatitis is not a contraindication to receiving this vaccine. * History of bleeding disorders * Any acute illness, including any fever (\> 100.4 F \[\> 38.0C\], regardless of the route) within 3 days prior to study entry \*. * Social, occupational, or any other condition that in the opinion of the investigator might interfere with compliance with the study and vaccine evaluation. Note: \*An individual who initially is excluded from study participation based on one or more of the time-limited exclusion criteria (e.g., acute illness, receipt or expected receipt of live or inactivated vaccines ) may be considered for enrollment once the condition has resolved as long as the subject continues to meet all other entry criteria. Subjects receiving \> 20 mg/day of prednisone or its equivalent daily or on alternate days for more than 2 weeks may enter the study after therapy has been discontinued for more than 3 months. \*\*Women of child-bearing potential (not surgically sterile via tubal ligation, bilateral oophorectomy or hysterectomy or who are not postmenopausal for ≥1 year) must agree to practice adequate contraception that may include, but is not limited to, relationship with vasectomized partner, barrier methods such as condoms, diaphragms, spermicides, intrauterine devices, and licensed hormonal methods for 30 days before and 90 days after zoster vaccination.