Influenza and pneumococcal vaccination uptake, knowledge, and perceived necessity in adults with chronic diseases: a cross-sectional study

Aims: Influenza and pneumococcal infections cause substantial morbidity and mortality among adults with chronic diseases; however, vaccination coverage remains suboptimal despite strong international recommendations. This study aimed to evaluate influenza and pneumococcal vaccination uptake, knowledge, attitudes, perceived necessity, and barriers among adults with chronic diseases. Methods: This descriptive cross-sectional study included adults (≥18 years) with at least one chronic disease attending an internal medicine outpatient clinic. Data were collected using a structured 11-item questionnaire assessing vaccination status, knowledge, physician recommendations, perceived necessity, and barriers. Associations were examined using Chi-square tests and Cramer’s V. Results: Among 200 participants, 49.00% had ever received an influenza vaccine and 20.50% were vaccinated in the previous year, while pneumococcal vaccination uptake was 14.60%. Awareness that influenza vaccination should be administered annually was reported by 30.50%, and 55.10% were aware of the pneumococcal vaccine. The most common barriers were lack of physician recommendation (57.90%), insufficient information (45.10%), and fear of adverse effects (41.40%). Knowledge of annual influenza vaccination was significantly associated with prior influenza vaccination (p<0.001; Cramer’s V=0.316). Pneumococcal vaccine recommendation was significantly associated with perceived necessity (χ²=19.68, df=6, p=0.003; Cramer's V=0.223). Conclusion: In this sample of adults with chronic diseases, only 20.50% had been vaccinated against influenza in the previous year and 14.60% had ever received a pneumococcal vaccine—well below guideline-recommended levels. Knowledge gaps and lack of physician recommendation emerged as the principal modifiable barriers. Targeted educational strategies and consistent physician engagement may improve vaccination coverage in high-risk populations.