Despite concerns of disease- or treatment-associated immunosuppression, a study published in the Journal of Clinical Oncology supports the recommendation for influenza vaccination in patients with cancer.
Researchers conducted an observational test-negative study of 24,46 adults (mean age, 70 years; 52% male) with previously diagnosed cancer who underwent influenza testing during the 2010 to 2011 and 2015 to 2016 flu seasons in Ontario, Canada. They assessed individual-level cancer registry, respiratory virus testing, and health administrative data. Vaccination status was determined from physician and pharmacist billing claims.
Patients’ mean time since cancer diagnosis was six years, 69% had solid-tumor cancers, and 23% received active chemotherapy.
Vaccine efficacy demonstrated in this patient population
The vaccine efficacy against laboratory-confirmed influenza was 21% (95% CI, 15-26), and vaccine efficacy against laboratory-confirmed influenza hospitalization was 20% (95% CI, 13-26).
For patients with solid tumors, vaccine efficacy was 25% (95% CI, 18-31), while vaccine efficacy for those with hematologic malignancies was just 8% (95% CI, –5-19; P=0.015). Active chemotherapy use did not significantly affect vaccine efficacy, particularly among those with solid tumors.