High Effectiveness Of Pcv13 Vaccine To Prevent Community-Acquired Pneumonia In Adults Over 65

Background: CAPiTA study found significant efficacy of 13-valent pneumococcal conjugate vaccine (PCV13) for first episode of vaccine-type community-acquired pneumonia (CAP), nonbacteremic/noninvasive vaccine-type CAP and vaccine-type CAP invasive pneumococcal disease. In 2012 a population-based surveillance of CAP aimed to estimate incidence rate of CAP in adults started in Roca City, Argentina (population older than 18 years old 62667, population 65 years and older 9312). Patients with radiographic confirmed diagnosis of CAP, treated on ambulatory basis or hospitalized, were invited to participate in the study and to sign inform consent. Preliminary results of the population-based surveillance showed a high incidence rate of CAP, particularly in elderly subjects. Based on this data a pilot vaccination program with PCV13 was implemented by the National and Provincial Ministry of Health offering PCV13 to subjects 65 years and older in Roca City. During a two years period 39% of subjects 65 years and older received PCV13. The aim of this analysis is to assess effectiveness of vaccination program to prevent all cause CAP in subjects 65 years and older. Methods & Materials: Cohort study assessed vaccine effectiveness in preventing CAP among adults 3 65 years and older. Data were gathered from the population-based surveillance database paired with national immunization registry during 2014-2016. Vaccine effectiveness was calculated (1 - (Incidence [vaccinated] ÷ Incidence [unvaccinated]). Multivariable logistic regression was performed, adjusted odds ratios (OR) were computed to obtain vaccine effectiveness (1-OR). We adjusted vaccine effectiveness for influenza vaccination status, age, chronic obstructive pulmonary (COPD), cardiovascular disease, diabetes and nephropathic diseases. Results: During the study period 3640 adults 65 years and older were vaccinated and 34 (0.93%) suffered CAP. In 5672 unvaccinated adults 65 years and older, 467 (8.23%) suffered the same event. Vaccine effectiveness was 90.0% (CI 95%: 85.0%-93.0%), p < 0.01. Adjusted vaccine effectiveness for influenza vaccination status, age, COPD, cardiovascular disease, diabetes and nephropathic diseases was 62.0% (CI 95%: 40.0-75.0), p < 0.01. Conclusion: Our results show a 62% effectiveness to prevent all cause CAP in adults 65 years and older. Studies of effectiveness are relevant to determine the role of PCV13 to prevent CAP in adults.