Assessment of adherence to routine vaccination schedules in oncology patients.

Introduction: Patients diagnosed with cancer are at an increased risk of infection. Vaccines remain one of the most critical public health strategies in limiting infectious diseases, with a heightened importance in cancer patients. Data across the general US population indicates that vaccine adherence rates are suboptimal across all adult vaccine schedules. This study aims to define vaccine adherence rates within the oncology population.

Methods: This retrospective cohort study includes adult patients with a new cancer diagnosis. Vaccine administrations for COVID-19 (SARS-CoV-2), influenza, pneumococcal, tetanus/diphtheria/pertussis (TDaP), herpes zoster (RZV), human papillomavirus (HPV), and hepatitis B (hepB) were assessed. The primary outcome was complete vaccine adherence.

Results: Two hundred and eighty-three oncology patients were included. The median age at diagnosis was 63 years old, and most subjects were females (60%). The two most common malignancies were gastrointestinal and breast cancer at 26.5% and 15.2%, respectively. Suboptimal vaccine adherence rates were observed across the entire oncology population. Complete adherence was observed in only 1.4% of patients. Vaccine specific adherence rates were as follows, SARS-CoV-2: 38.9%; influenza: 11.4%; pneumococcal: 12.7%; TDaP: 13.1%; RZV: 3.5%; HPV: 0%; and hepB: 34%. Among the vaccine schedules assessed, SARS-CoV-2 vaccination rates were the highest with 38.9% of patients being fully adherent and 73% receiving at least one dose.

Conclusion: Lower vaccine adherence rates were observed in oncology patients compared to currently published rates. Providers and pharmacists can play a role in assessing and counseling patients on the importance of vaccine adherence before chemotherapy is initiated and after a remission is obtained.