In the first part of this study we found the highest dose of the vaccine that did not have too many side effects. We are now trying to find out what effects the vaccine has when given at the same dose to all patients. The main treatment in this protocol is a vaccine. It is called a " bivalent vaccine" which means it has 2 antigens. An antigen is a specific protein on the surface of a cell. The antigens are called GD2L and GD3L. We want the vaccine to cause the patient's immune system to make antibodies against the antigens. Antibodies are made by the body to attack cancer (and to fight infections). If the patient can make antibodies against the 2 antigens in the vaccine, those antibodies might also attach to neuroblastoma cells because a lot of each antigen is on neuroblastoma (and very little on other parts of the body). Then, the attached antibodies would attract the patient's white blood cells to kill the neuroblastoma. This protocol also uses β-glucan which is a kind of sugar from yeast. β-glucan is taken by mouth and can help white blood cells kill cancer. The best way to get the body to make antibodies against the 2 antigens is to link each antigen to a protein called KLH (which stands for: keyhole limpet hemocyanin) and to mix them with a substance called QS-21. But it is hard to get enough QS-21 so we are using an identical substance called OPT-821, which we can get easily in large amounts for use in patients.

The phase II treatment schema for patients in 1st CR or ≥ 2nd CR will be the same for the vaccine as in phase I except OPT-821 will be given at a fixed dose of 150 mcg/ m\^2 and with no DLT assessment. Patients will be randomized to starting oral β-glucan in week 1 or in week 6.