This is a Phase 1 and Phase 2 study of a single vaccination with one of three dose levels of a 4-antigen investigational vaccine against Staphylococcus aureus (SA4Ag) and a single dose level of a 3-antigen Staphylococcus aureus vaccine (SA3Ag). The main goal of the study is to determine how safe and well tolerated the vaccine is as well as to describe the immune response elicited by the vaccine in healthy adults aged 65 to <86 years. In addition, the study aims to assess the effect of the Staphylococcus aureus vaccine on the presence of the Staphylococcus aureus within the nose, throat and perineal skin of healthy adults aged 65 to <86 years.

Inclusion Criteria:

• Healthy males and healthy postmenopausal females, aged 65 to <86 years at enrollment, as determined by medical history, physical examination, and the clinical judgment of the investigator to be eligible for the study. Subjects with preexisting chronic medical conditions determined to be stable may be included.
• Available for the entire duration of the study, and able to comply with scheduled visits, study plan, laboratory tests, and other study procedures including completion of the electronic diary (e diary) from Day 1 to Day 14 following vaccination.
• Able to be contacted by telephone during study participation.
• Male subjects who, in the opinion of the investigator, are biologically capable of fathering children, and who are sexually active with women of childbearing potential must agree to use a highly effective method of contraception throughout the study.

Exclusion Criteria:

• Unstable chronic medical condition or disease requiring significant change in therapy or hospitalization for worsening disease within 3 months before receipt of study vaccine.
• Serious chronic medical disorders or any disorder that in the investigator's opinion precludes the subject from participating in the study.
• Donation of blood volume of 250 mL or greater or donation of plasma within 3 months prior to enrollment through conclusion of the study.
• Bleeding condition associated with prolonged bleeding time that may contraindicate intramuscular injection or blood draw including subjects taking anticoagulant, antiplatelet and/or antithrombotic agents except for low-dose daily aspirin within 30 days before enrollment through completion of Visit 6 (Day 29).
• Any contraindication to vaccination or vaccine components, including previous anaphylactic reaction to any vaccine or vaccine related components.
• Immunocompromised persons or subjects currently on immunosuppressive therapy or with a history of immunosuppressive therapy. History of immune-modifying drugs.
• Previous administration of S. aureus vaccination.
• Any infection proven or suspected to be caused by S. aureus within 6 months preceding study vaccination.
• Receipt of blood products or immunoglobulins (including monoclonal antibodies) within 12 months before enrollment through conclusion of the study.
• Participation in other investigational or interventional studies within 30 days before the current study begins and/or during study participation. Participation in purely observational studies is acceptable.
• Subjects who are investigational site staff members or subjects who are immediate family members (first-degree relatives) of investigational site staff members or Pfizer employees directly involved in the conduct of the trial.
• Residence in a nursing home or long-term care facility or requirement for semiskilled nursing care. An ambulatory subject who is a resident of a retirement home or village is eligible for the trial.
• A Mini-Mental State Examination (MMSE) score of ≤21.
• For Phase 1 subjects only, any abnormality in screening hematology, coagulation, and/or blood chemistry laboratory values except as noted in protocol
• Subjects with known active disease with human immunodeficiency virus (HIV), hepatitis B virus (HBV), and/or hepatitis C virus (HCV), or Phase 1 subjects with a positive screening test for HIV, HBV and/or HCV.
• Other severe acute or chronic medical or psychiatric condition or laboratory abnormality that may increase the risk associated with study participation or investigational product administration or may interfere with the interpretation of study results and, in the judgment of the investigator, would make the subject inappropriate for entry into this study.
• Planned surgical procedure within 30 days following vaccination.