Eligible research subjects will be randomized to receive either FluMist or inactivated influenza vaccine then stratified by age and necessity to receive either one or two immunizations. Subjects requiring one immunization will be immunized at Day 0. Subjects requiring two immunizations will be immunized at Day 0 and Day 28. Subjects will be observed for 30 minutes following vaccination and given a diary card to record symptoms after each vaccination.

The secondary objectives of this study are to:

1. Describe the safety of FluMist and inactivated influenza vaccine.
2. Describe the incidence and duration of viral replication following immunization with FluMist.
3. To examine the association between immunization response (seroconversion or seroprotection) and baseline clinical factors (age, type of malignancy, absolute neutrophil count, absolute lymphocyte count, serum IgA, IgG and IgM levels).

Inclusion Criteria:

• Age 2 through 21 (not yet reached their 22nd birthday) at the time of entry into the study
• Participant or participants parent/legal guardian available by telephone during the course of the study;
• Written informed consent (and assent, if applicable) obtained
• Currently receiving chemotherapy and /or radiotherapy for the treatment of cancer or have received chemotherapy in the past 12 weeks;
• If the participant's underlying cancer is a solid tumor, current status must be stable disease, partial response, or complete response to therapy; if the participant's underlying disease is a hematological malignancy, current status must be in remission, and if receiving chemotherapy, must be in the "continuation" or "maintenance" phase of therapy or equivalent;
• Estimated life expectancy of > 1 year

Exclusion Criteria:

• History of hypersensitivity to any component of FluMist or TIV, including egg or egg products, gelatin, or monosodium glutamate;
• History of hypersensitivity to gentamicin;
• Close contact with a severely immunocompromised patient (e.g., a hematopoietic stem cell transplant patient, during those periods in which the immunocompromised patient requires care in a protective environment
• History of Guillain-Barre´ syndrome;
• History of asthma;
• Female who is breastfeeding or lactating;