Factors associated with influenza, COVID-19, and pneumococcal vaccinations in patients with chronic obstructive pulmonary disease: a cross-sectional study in a Thai university hospital

Vaccination against influenza, coronavirus disease 2019 (COVID-19), and pneumococcal disease is recommended for patients with chronic obstructive pulmonary disease (COPD) to reduce severe infections, pneumonia, and acute exacerbations. However, vaccination coverage in this population remains suboptimal. This study aimed to assess the proportion of COPD patients receiving these vaccinations and to identify factors associated with vaccine uptake. A cross-sectional study was conducted among COPD patients receiving regular follow-up at a single tertiary care hospital in Thailand in 2025. Data on demographic characteristics, comorbidities, vaccination status, and clinical outcomes, including acute exacerbations and hospitalizations, were collected. Univariable logistic regression was used to explore factors associated with each vaccination outcome; multivariable logistic regression was performed only for pneumococcal vaccination because of the small numbers of participants who were unvaccinated against influenza and COVID-19. Of 377 COPD patients screened, 145 met the eligibility criteria, and 138 patients (84.8% male) consented and were included in the final analysis. Vaccination coverage was 89.9% for influenza, 91.3% for COVID-19, and 23.2% for pneumococcal vaccines. Malignancy was more common among participants who received pneumococcal vaccination (OR 3.74, 95% CI 1.01–13.87; P = 0.048). ASCVD (OR 0.31, 95% CI 0.09–1.04; P = 0.058) and stroke/TIA (OR 0.21, 95% CI 0.06–0.80; P = 0.023) were less common among participants who received COVID-19 vaccination. In multivariable analysis, BMI > 23.5 kg/m 2 and malignancy were independently associated with pneumococcal vaccination, with adjusted ORs of 2.44 (95% CI 1.07–5.56; P = 0.035) and 4.10 (95% CI 1.07–15.80; P = 0.040), respectively. Multivariable models were not fitted for influenza or COVID-19 vaccination because of the small numbers of unvaccinated participants. The most commonly reported reasons for non-vaccination were the perception that vaccination was unnecessary, lack of physician recommendation, and concerns regarding adverse effects. Pneumococcal vaccination coverage among patients with COPD remains low, whereas influenza and COVID-19 vaccination rates are relatively high. Knowledge gaps and insufficient physician recommendation remain major barriers to vaccine uptake, underscoring the need for enhanced patient education and greater clinician engagement to improve vaccination coverage in this high-risk population.