The purpose of this study is to determine whether influenza vaccination protects patients who receive a certain type of bone marrow transplantation.

Patients who receive bone marrow transplantation are at high risk for complications from influenza infection. It is not whether influenza vaccination protects patients who undergo a type of bone marrow transplantation called "nonmyeloablative", or "reduced intensity" bone marrow transplantation. This study compares the response to influenza vaccination in a group of these patients to that in healthy people.

Inclusion Criteria:

• Patients were included if they had received RIC allo HSCT 3 months or more prior to enrollment, and were between the age of 18 and 65 years.
• Controls were health care providers at our institution, between the ages of 18 and 65 years, who were in good health, and who are routinely offered influenza vaccination.

Exclusion Criteria:

• Patients were excluded if they failed to engraft, or had relapse of the underlying disease requiring chemotherapy or immunotherapy.
• Patients and controls were also excluded if they had history of egg allergy, acute febrile illness at the time of vaccination, or influenza-like illness within 4 weeks prior to vaccination.