By the way, in comparison to placebo and the single components, a superior control by means of the inhaled corticosteroids (ICS)/long-acting beta2-agonist (LABA) fixed combination therapy has been demonstrated for significant clinical improvement in moderate-to-severe COPD patients, except mortality, by meta-analysis and large prospective studies (TORCH [Towards a Revolution in COPD Health] trial and INSPIRE [Investigating New Standards for Prophylaxis in Reduction of Exacerbations] trial). However, those database indicated that high daily dose of ICS (fluticasone propionate at a dose of 500-1000mcg daily) was associated with an excess risk of pneumonia, which doubles the pneumonia incidence in patients not receiving ICS. The immunogenicity of PPSV23 in COPD patients using systemic steroid was demonstrated but the clinical efficacy of vaccination has not been investigated.