Uptake of vaccination in older Indian patients with cancer: A cross-sectional observational study

Background: Older patients with cancer are at a higher risk of invasive infections. Vaccination is an effective approach to decrease the mortality and morbidity associated with infections. Objectives: Our primary objective was to evaluate the proportion of older patients with cancer who had received routine vaccinations against pneumococcal, influenza, and coronavirus disease 2019 (COVID-19). Our secondary objective was to identify the factors associated with vaccine uptake such as age, sex, education, marital status, comorbidities, and place of residence. Materials and Methods: This cross-sectional observational study was conducted in the geriatric oncology outpatient clinic of the Department of Medical Oncology at the Tata Memorial Hospital, a tertiary care cancer hospital in Mumbai, India, from February 2020 to January 2023. We included all patients aged ≥60 years who were evaluated in the geriatric oncology clinic during the study period and for whom the immunization details were available. The uptake of COVID-19 vaccine was calculated from March 2021 onwards, which was when the COVID-19 vaccine became available to patients aged ≥60 years in India. Results: We enrolled 1762 patients; 1342 (76.2%) were male. The mean age was 68.4 (SD, 5.8) years; 795 (45%) patients were from the west zone of India. Only 12 (0.68%) patients had received the pneumococcal vaccine, and 13 (0.7%) had received the influenza vaccine. At least one dose of the COVID-19 vaccine had been taken by 1302 of 1562 patients (83.3%). On univariate logistic regression, education, marital status, geographic zone of residence, and primary tumor site were correlated with the uptake of COVID-19 vaccine. Factors associated with a greater COVID-19 vaccine uptake included education (up to Std 10 and higher vs. less than Std 10: Odds Ratio [OR], 1.46; 95% confidence interval [CI], 1.07-1.99; P = 0.018, and illiterate vs. less than Std 10: OR, 0.70; 95% CI, 0.50-0.99; P = 0.041), marital status (unmarried vs. married: OR, 0.27; 95% CI, 0.08-1.08; P = 0.046, and widow/widower vs. married: OR, 0.67; 95% CI, 0.48-0.94; P = 0.017), lung and gastrointestinal vs. head-and-neck primary tumors (lung cancer vs. head-and-neck cancer: OR, 1.60; 95% CI, 1.02–2.47; P = 0.038, and gastrointestinal vs .head-and-neck cancer: OR, 2.18; 95% CI, 1.37-3.42; P < 0.001), and place of residence (west zone vs. central India: OR, 0.34; 95% CI, 0.13-0.75; P = 0.015). Conclusion: Fewer than 1 in 100 older Indian patients with cancer receive routine immunization with influenza and pneumococcal vaccines. Hearteningly, the uptake of COVID-19 vaccination in older Indian patients with cancer is over 80%, possibly due to the global recognition of its importance during the pandemic. Similar measures as those used to increase the uptake of COVID-19 vaccines during the pandemic may be beneficial to increase the uptake of routine vaccinations (Clinical Trials Registry, India: CTRI/2020/04/024675).