Subjects who have completed study 6108A1-500, in which our experimental meningoccal B vaccine or placebo was administered, will be approached for inclusion into this study which is purely for blood draw. The sera will be used for assay development.

The purpose of this protocol is to analyze the collection of blood volumes (approximately 200 to 470 mL per bleed) from volunteer donors who previously completed study 6108A1-500. As such, the inclusion and exclusion criteria are consistent with the Australian Red Cross guidelines for blood donation.

The 6108A1-500 study is an ongoing, double-blind, ascending-dose, randomized, placebo-controlled trial to assess the safety and tolerability of ascending doses of rLP2086 with aluminum phosphate (AlPO4) adjuvant, in healthy adults aged 18 to 25 years. Upon completion of participation in the 6108A1-500 study, subjects will be approached to participate in this blood sampling study. The sites participating in this blood sampling study are the same sites participating in the 6108A1-500 study.

Main Inclusion Criteria:

1. Completed study 6108A1-500.
2. Hemoglobin level ≥12.0 and ≤16.5 g/dL for female subjects and ≥13.0 and ≤18.5 g/dL for male subjects.
3. Body weight ≥45 and ≤120 kg.
4. Systolic blood pressure >90 and <180 mm Hg.
5. Diastolic blood pressure >60 and <100 mm Hg.
6. Able to be contacted by telephone.
7. For all female subjects: have a negative urine pregnancy test unless the subject is surgically sterile.

Main Exclusion Criteria:

1. Bleeding diathesis or condition associated with prolonged bleeding time.
2. Prior antibiotic use (within 14 days).
3. Any clinically significant chronic disease that, in the investigator's judgment may be worsened by blood draw.