Pneumococcal vaccination status in critically ill patients: A cross-sectional study

Critically ill adults are often older and have multiple chronic conditions, but data on prior pneumococcal vaccination in this population are limited. We aimed to assess pneumococcal vaccination coverage among eligible patients and identify factors associated with pneumococcal vaccination among ICU patients. We performed a cross-sectional study in an ICU at a tertiary care hospital in Japan. We included patients admitted to the ICU from May 15, 2023, to January 4, 2024. Eligibility for pneumococcal vaccination was defined with reference to the Japanese routine vaccination program during the study period. Vaccination status for pneumococcal, influenza, and coronavirus disease 2019 (COVID-19) vaccines was assessed using a structured questionnaire administered to patients or family members during ICU admission. Multivariable logistic regression analysis was performed among eligible patients with known pneumococcal vaccination status. Among 982 patients, 757 (77.1%) met pneumococcal vaccination eligibility criteria. After excluding 32 non-responders, vaccination status was assessed for 725 eligible patients. Of these, 124 (17.1%) reported pneumococcal vaccination, 371 (51.2%) reported no pneumococcal vaccination, and 230 (31.7%) reported unknown status. In the multivariable analysis, influenza vaccination was the only factor independently associated with reported pneumococcal vaccination status (odds ratio, 31.8, 95% confidence interval, 4.3–236.7, p < .001). Our study highlights that most ICU patients were eligible for pneumococcal vaccination, but a minority of eligible patients reported vaccination, and approximately one-third had unknown vaccination status. These findings support the need for more reliable vaccination records and routine opportunities to assess eligibility and history in this population.