Duration of hSBA Response After a Primary Series of Bivalent rLP2086 Followed by a Booster Dose

This study is to assess the longevity of immune responses in adolescents (aged 10 to \<19 years at the time of entry into a primary study) following receipt of a vaccination regimen of 2 or 3 doses of bivalent rLP2086 in a primary study. A booster dose of bivalent rLP2086 at approximately 48 months was given following the final dose of the 2- or 3-dose primary bivalent rLP2086 vaccination series. The study was therefore divided into Stage 1 (4-year persistence of immune responses following receipt of a primary vaccination series) and the booster stage (follow-up through 12 months for all boosted or 26 months for a subset of the boosted). Subjects participating only in Stage 1 will attend up to 6 study visits for collection of a 20-mL blood sample at each visit. Subjects participating in both Stage 1 and booster stage will attend up to 9-10 study visits with 1 visit for booster dose vaccination and 8-9 visits for collection of a 20-mL blood sample at each visit.