RATIONALE: Flu vaccine may help the body build an immune response and decrease the occurrence of flu in children who are receiving chemotherapy for acute lymphoblastic leukemia.

PURPOSE: Clinical trial to study the effectiveness of vaccine therapy in preventing flu in children who have acute lymphoblastic leukemia.

OBJECTIVES:

• Determine the immune response, in terms of the formation of protective antibody titers to influenza, in children with acute lymphoblastic leukemia treated with split-virus trivalent influenza vaccine.
• Correlate the formation of protective antibody titers following immunization with the absolute neutrophil counts and absolute lymphocyte counts in these patients at the time of vaccination.

OUTLINE: This is a multicenter study. Patients are stratified according to current treatment for acute lymphoblastic leukemia (consolidation chemotherapy vs maintenance chemotherapy vs off therapy for the past 6 months).

Patients receive split-virus trivalent influenza vaccine intramuscularly once or twice at 4 weeks apart for 2 doses.

Patients are followed at week 5. Patients receiving 2 doses of vaccine are also followed at week 9.

PROJECTED ACCRUAL: A total of 175 patients (50 receiving consolidation therapy, 75 receiving maintenance therapy, and 50 off therapy) will be accrued for this study within 2 years.

• Infection
• Leukemia

DISEASE CHARACTERISTICS:

• Diagnosis of acute lymphoblastic leukemia

  • In first remission after completion of induction chemotherapy
  • Currently on active treatment OR
  • Completed treatment within the past 6 months

PATIENT CHARACTERISTICS:

Age:

• 1 to 20 at time of diagnosis

Performance status:

• Not specified

Life expectancy:

• Not specified

Hematopoietic:

• Not specified

Hepatic:

• Not specified

Renal:

• Not specified

Pulmonary:

• No acute respiratory distress

Other:

• No history of Guillain-Barre syndrome
• No history of hypersensitivity to chicken eggs, egg products, or components of influenza virus vaccine, including thimerosal
• No febrile illness with fever over 100.4 degrees F
• Not pregnant or nursing
• Fertile patients must use effective contraception

PRIOR CONCURRENT THERAPY:

Biologic therapy:

• Not specified

Chemotherapy:

• See Disease Characteristics

Endocrine therapy:

• Not specified

Radiotherapy:

• Not specified

Surgery:

• Not specified

Other:

• At least 7 days since prior antibiotic or antiviral therapy except prophylactic antibiotics