Inclusion Criteria:

- Diagnosis of neuroblastoma (NB) as defined by international criteria,[104] i.e.,
histopathology (confirmed by the MSKCC Department of Pathology) or bone marrow
metastases plus high urine catecholamine levels.

- High-risk NB as defined by risk-related treatment guidelines and the International NB
Staging System,[104] i.e., stage 4 with (any age) or without (>18 months old) MYCN
amplification, MYCN-amplified stage 3 (unresectable; any age), MYCN-amplified stage
4S, or disease resistant to standard chemotherapy.

- Relapsed high-risk NB (as defined above) and now in second or subsequent remission.
Remission is defined as complete (CR) or very good partial (VGPR)remission,
according to the International Neuroblastoma Response Criteria.[104] Urine
catecholamine levels are no longer taken into consideration when staging.

Patients can be considered as in VGPR with 1 or 2 MIBG (+) sites that were previously-
irradiated.

- Absolute lymphocyte count > or = to 500/mcl and absolute neutrophil count > or = to
500/mcl.

- Creatinine ≤ 2.0 mg/dL

- ALT, AST and Alkaline Phosphatase ≤ 2.5 times the upper limit of normal

- Bilirubin ≤ 2.0 mg/dL

- Patients with less than grade 3 toxicities (using the CTCAE v3.0) related to cardiac,
neurological, pulmonary or gastrointestinal function as determined by physical exam.

- Prior treatment with other immunotherapy, including antibodies, is allowed

- > or = to 3 weeks between completion of systemic therapy and 1st vaccination.

- Signed informed consent indicating awareness of the investigational nature of this
program.

Exclusion Criteria:

- History of allergy to KLH, QS-21, OPT-821, or glucan.

- Active life-threatening infection.

- Inability to comply with protocol requirements.