Pfizer says study found Prevnar 13 reduces the risk of hospitalization
Pfizer announced that results from a study analyzing real-world effectiveness data found that Prevnar 13 reduced the risk of hospitalization from vaccine-type pneumococcal community-acquired pneumonia by 73% in adults aged 65 and older. Importantly, Prevnar 13 worked under real-world conditions where people received pneumococcal vaccination as advised by their health care providers, and many had underlying medical conditions that increase the risk for pneumococcal pneumonia.1 The results were published in Clinical Infectious Diseases. The study, conducted jointly between the University of Louisville School of Medicine and Pfizer, was designed as a test-negative case-control study and provides evidence supporting the findings of the landmark randomized, controlled Community-Acquired Pneumonia Immunization Trial in Adults. CAPiTA was one of the largest vaccine efficacy trials ever conducted in older adults and demonstrated a significant reduction by 45.6% in vaccine-type pneumococcal CAP in adults vaccinated with PCV13. The Community-Acquired Pneumonia Immunization Trial in Adults excluded people with high-risk medical conditions.2The safety profile of PCV13 in CAPiTA was consistent with studies previously conducted in adults. The study was nested within a population-based surveillance study of adults in Louisville, Kentucky, United States, who were hospitalized with CAP. The population-based surveillance study prospectively enrolled adults in Louisville, Kentucky who were hospitalized with CAP in one of nine adult acute-care hospitals between October 7, 2013 and September 30, 2016. The nested case-control sub-study analyzed a subset of CAP patients enrolled between April 1, 2015 and April 30, 2016. The study used an established measure of vaccine effectiveness known as a test-negative design. In this study, patients hospitalized with CAP had routine cultures performed as well as a urine antigen detection test to determine if they had infections with pneumococcal serotypes included in the vaccine, PCV13. Patients with pneumonias caused by pneumococcal serotypes included in PCV13 were considered "cases," and "control" subjects were patients with CAP who tested negative for PCV13 serotypes. In the study period, there were a total of 2,034 CAP hospitalizations with a median age of 76 years. Researchers identified PCV13 serotypes in 68 of patients who served as the case subjects. Cases were less likely to have received PCV13 vs. controls. This indicated that PCV13 use in adults aged 65 and older can prevent 73% of CAP caused by PCV13 serotypes.