Prevention and Management of Influenza in Patients Undergoing Anticancer Therapy

Influenza causes substantial, yet preventable, morbidity and mortality and poses a particularly high risk to patients with cancer, in whom both the disease itself and systemic anticancer therapies can lead to immunosuppression.This review summarizes key updates in influenza prevention and management in these patients.Considering the apparent disappearance of the B/Yamagata lineage globally, influenza vaccines have transitioned from quadrivalent to trivalent formulations, while high-dose, adjuvanted, and cell culture-based vaccines have been developed to improve responses in older and immunocompromised hosts.Although patients with cancer demonstrate reduced vaccine immunogenicity, evidence shows that vaccination significantly decreases influenza-related complications, thereby justifying strong recommendations for routine vaccination.In diagnostics, real-time polymerase chain reaction and multiplex respiratory virus panels have replaced low-sensitivity rapid antigen tests, enabling earlier and more reliable diagnosis and timely antiviral use.Neuraminidase inhibitors remain the first-line therapy, with baloxavir marboxil, a cap-dependent endonuclease inhibitor, serving as a single-dose oral alternative.However, atypical presentations, prolonged viral shedding, and antiviral resistance can occur in this group.Therefore, combining optimized vaccination, proactive molecular testing, and prompt, individualized antiviral therapy is essential to reduce influenza-associated morbidity and mortality in patients undergoing anticancer treatment.