Influenza Vaccine Effectiveness Among Patients With Cancer: A Population-Based Study Using Health Administrative and Laboratory Testing Data From Ontario, Canada

Abstract

PURPOSE Seasonal influenza vaccination is recommended for patients with cancer despite concerns of disease or treatment-associated immunosuppression. The objective of this study was to evaluate vaccine effectiveness (VE) against laboratory-confirmed influenza for patients with cancer. PATIENTS AND METHODS We conducted an observational test-negative design study of previously diagnosed patients with cancer 18 years of age and older who underwent influenza testing during the 2010-2011 to 2015-2016 influenza seasons in Ontario, Canada. We linked individual-level cancer registry, respiratory virus testing, and health administrative data to identify the study population and outcomes. Vaccination status was determined from physician and pharmacist billing claims. We used multivariable logistic regression to estimate VE, adjusting for age, sex, rurality, income quintile, cancer characteristics, chemotherapy exposure, comorbidities, previous health care use, influenza season, and calendar time. RESULTS We identified 26,463 patients with cancer who underwent influenza testing, with 4,320 test-positive cases (16%) and 11,783 (45%) vaccinated. Mean age was 70 years, 52% were male, mean time since diagnosis was 6 years, 69% had solid tumor malignancies, and 23% received active chemotherapy. VE against laboratory-confirmed influenza was 21% (95% CI, 15% to 26%), and VE against laboratory-confirmed influenza hospitalization was 20% (95% CI, 13% to 26%). For patients with solid tumor malignancies, VE was 25% (95% CI, 18% to 31%), compared with 8% (95% CI, –5% to 19%) for patients with hematologic malignancies ( P = .015). Active chemotherapy usage did not significantly affect VE, especially among patients with solid tumor cancer. CONCLUSION Our results support recommendations for influenza vaccination for patients with cancer. VE was decreased for patients with hematologic malignancies, and there was no significant difference in VE among patients with solid tumor cancer receiving active chemotherapy. Strategies to optimize influenza prevention among patients with cancer are warranted.

Prevalence of COVID-19-related risk factors and risk of severe influenza outcomes in cancer survivors: a matched cohort study using linked English electronic health records data

“…Our primary outcome combined influenza hospitalisations and deaths but was dominated by the former; it is plausible that there may be a lower threshold for hospitalisation in cancer survivors which could have exaggerated the difference in risk of the primary outcome between cancer survivors and controls, but is unlikely to fully explain the large associations we observed. Finally, we had some missing data on smoking and BMI data, and we excluded those with missing data from the analysis; this is unlikely to affect our findings under the Improving influenza vaccination coverage among cancer survivors should be a priority, as the vaccine is both effective and safe 29,30 but coverage has been reported in the range of 50% to 76% among cancer survivors in the US and in the UK. 31,32 Immunisation for streptococcus pneumoniae may also be considered.…”

“…Our results also have implications for preventive medicine in the coming autumn and winter, when influenza and SARS-CoV-2 are expected to coexist in the population. Improving influenza vaccination coverage among cancer survivors should be a priority, as the vaccine is both effective and safe 29,30 but coverage has been reported in the range of 50% to 76% among cancer survivors in the US and in the UK. 31,32 Immunisation for streptococcus pneumoniae may also be considered.…”

COVID-19 and Cancer: a Comprehensive Review

“…However, virus eliminating immune response may be difficult to illicit in immunocompromised cancer patients. Vaccine effectiveness in general tends to be lower in patients with cancer, much lower for those with hematologic malignancies [75]. Utilization of long-term immune memory from convalescent individuals may provide alternate strategies for patients with hematological malignancies.…”

Safety, Efficacy and Acceptability of SARS-CoV-2 Vaccines in Patients With Cancer

“…All of these factors highlight the complexity and the steep learning curve in understanding thoroughly this process, as well as the challenges faced in answering questions related to the many possible scenarios. The efficacy of other types of vaccines in patients with cancer has been previously evaluated, with conflicting results: while some studies investigating influenza vaccines have previously shown substantial efficacy in cancer patients [ 23 , 24 ], others have shown decreased or nondurable immune responses [ 25 , 26 ]. This further highlights the heterogeneity and complexity of immune responses in this specific population.…”