Should Cancer Patients Receive the Flu Vaccine?

By infecting 5% to 10% of the US population each year, influenza consumes $87.1 billion.

Patients aged 65 years or older and those who are immunosuppressed are most susceptible to serious infection.

Cancer patients frequently have double the risk because the median age at cancer diagnosis is 67 years old, and many chemotherapy regimens are immunosuppressive.

Memory B and T cells inhibiting hemagglutinin mediate immunologic response to the influenza vaccine.

A minority of cancer patients receive the influenza vaccine due to physicians’ safety and adverse effect misconceptions. The studies upon which these beliefs are based are up to 40 years old, combined solid and hematologic cancers together, and measured seroconversion only.

American Journal of Clinical Oncology has published a well-structured study that demonstrated that patients receiving chemotherapy for non-hematologic cancers are able to stage an immune response to influenza vaccination.

Patients received an intramuscular trivalent 2011-2012 influenza season vaccine dose either on the day of chemotherapy or 1 week prior.

The researchers collected hemagglutination inhibition assays for influenza A (H1N1), A (H3N2), and B at baseline and 4 weeks after vaccination. Then, they screened these assays for signs of seroconversion (greater than a 4-fold increase in titer levels) and seroprotection (greater than a 40-fold increase).

Patients responded well to inactivated influenza vaccination when receiving modern chemotherapy regimens.

Vaccination timing did not affect seroconversion and seroprotection.

The study authors excluded patients receiving systemic corticosteroids and those with a baseline absolute neutrophil count less than 1000 cells/mm³ in order to isolate the impact of chemotherapy itself.

The study is limited because the researchers enrolled only 18 patients and no patients with certain cancers (breast, genitourinary tract, central nervous system, and melanoma).

The study authors said they believed this study acts as a pilot study for an adequately powered prospective study stratified by cancer and chemotherapy regimen.

The researchers affirmed that all patients should receive an influenza vaccination unless contraindicated.