Efectividad de la vacunación antineumocícica en la población mayor de 65 años
BACKGROUND: Infecctions caused by Streptococcus Pneumoniae are an important cause of morbidity and mortality in the elderly, especially in those with chronic diseases. The 23-valent polysaccharide pneumococcal vaccine (PPV) has been available since 1983 and is currently recommended for use in the elderly and high-risk groups. People over 65-years soffer the greatest burden of infection and death by pneumonia and they are the greatest target group for pneumococcal vaccination. However, despite numerous studies, the effectiveness of 23-valent PPV in the prevention of pneumococcal infections and other clinically relevant medical outcomes remains unclear in general elderly population and high-risk elderly subjects.
OBJECTIVE: The present study assessed the effectiveness of the 23-valent pneumococcal polysaccharide vaccine to prevent pneumococcal disease, pneumonia and death in older adults.
METHODS: A prospective cohort study was conducted between January 2002 and April 2005, including all individuals >65 yrs of age assigned to 8 Primary Care Centres in Tarragona, Spain (n=11,241). The primary outcomes were invasive pneumococcal disease, pneumococcal pneumonia, overall pneumonia (hospitalised or outpatient) and death from pneumonia. All pneumonias were validated by checking clinical records. The association between the pneumococcal vaccination and the risk of each outcome was evaluated by means of multivariate Cox proportional-hazard models, adjusted by age, sex, comorbidity, inmunological situation, and influenza vaccination situation, Pneumococcal vaccine status was a time-varying covariate, ant other covariate were defined at study entry.
RESULTS: Pneumococcal vaccination was effective to prevent invasive pneumococcal disease (hazard ratio (HR): 0.41; 95% confidence interval (CI): 0.13-0.99), bacteraemic pneumococcal pneumonia (HR: 0.36; 95% CI: 0.13-0.99) and non-bacteraemic pneumococcal pneumonia (HR: 0.48 ; 95% CI: 0.26-0.90), but the vaccine did not alter significantly the risk of hospitalisation from pneumonia (HR: 0.82; 95% CI: 0.64-1.04) or overall pneumonia (HR: 0.83; 95% CI: 0.67-1.03). The pneumococcal vaccine was associated with considerable reductions of death risk from pneumonia (HR: 0.40; 95% CI: 0.22-0.71) and death risk from pneumococcal infection (HR: 0.43; CI 95%: 0.10-1.76).
CONCLUSSIONS: These results suggest that the pneumococcal polysaccharide vaccine may not be effective in reducing the incidence of overall pneumonia, but may be able to diminish the incidence and severity of the pneumococal infections. These findings confirm the effectiveness of 23-valent PPV to prevent IPD, but its also show a protective effect against non-bacteraemic pneumococcal pneumonia and mortality caused by pneumonia in older adults, providing a new arguments to recommend systematic vaccination in elderly subjects..
KEYWORDS: effectivenees, elderly, pneumococcal vaccine, community-acquired pneumonia, pneumococcal pneumonia, invasive pneumococcal disease, death.
Advisor:Llor Vila, Carles; Bladé Creixenti, Jordi
School:Universitat Rovira i Virgili
Source Type:Master's Thesis
Keywords:departament de medicina i cirurgia
Date of Publication:03/10/2006