(303) Cardiovascular, neurological, and immunological adverse events associated with 23-valent pneumococcal polysaccharide vaccine among older adults: a nationwide self-controlled risk interval study

Publication Number: 1293

Background: A 23-valent pneumococcal polysaccharide vaccine (PPSV23) is recommended as a preventative measure for pneumonia, one of the leading causes of mortality in older adults. However, concerns remain as to the adverse events following PPSV23 due to lack of statistical power and largely outdated evidence.

Objectives: To evaluate the association of cardiovascular, neurological, and immunological adverse events associated with PPSV23 among older adults using self-controlled risk interval (SCRI) design.

Methods: Using a large-linked database created by linking the Korea Immunization Registry Information System and the National Health Information Database (2018-2021), we included patients aged 65 years or older with a history of both PPSV23 vaccination and incident diagnosis of outcome during the risk- and control intervals. Outcomes included three disease categories, classified into acute and subacute based on its pathophysiology: (1) cardiovascular (acute: myocardial infarction; subacute: atrial fibrillation, cardiomyopathy, heart failure), (2) neurological (acute: Bell’s palsy, Guillain- Barré syndrome), and (3) immunological (acute: sepsis; subacute: thrombocytopenia). The risk- and control intervals were defined as 1-28 and 57-112 days after PPSV23 vaccination for acute outcomes, and 1-84 and 113-196 days for subacute outcomes, respectively. We applied wash-out interval of 28 days between the risk- and control intervals to avoid potential outcome misclassification. We used conditional Poisson regression to estimate the incidence rate ratio (IRR) with 95% confidence interval (CI). Sensitivity analysis was conducted by varying the risk- and wash-out intervals.

Results: Among 1,802,739 of PPSV23 vaccinated population, 4,355 patients were included. The mean age at vaccination was 72.4 and 52.1% were male. In each SCRI analysis, none of the outcomes revealed increased risk following PPSV23 vaccination. For cardiovascular adverse events, myocardial infarction (IRR 0.96, 95% CI 0.80-1.15), atrial fibrillation (0.93, 0.82-1.06), cardiomyopathy (0.81, 0.59-1.10) showed no significant association, while reduced risk were found for heart failure (0.84, 0.74-0.95) following PPSV23. No significant association was observed in both neurological and immunological outcomes: Bell’s palsy (0.89, 0.66-1.19), and sepsis (1.02, 0.87-1.19). Results from sensitivity analysis were consistent with the main findings.

Conclusions: No evidence of association was found for cardiovascular, neurological, and immunological adverse events following PPSV23. The updated safety profiles of PPSV23 could be utilized as supportive evidence for establishing strategies to prevent pneumonia.