Abstract
CONTEXT: Invasive pneumococcal disease (IPD) and pneumonia are a leading cause of morbidity and mortality throughout the world, and asthma is the most common chronic disease of childhood. OBJECTIVE: To evaluate the risk of IPD or pneumonia among children with asthma after the introduction of pneumococcal conjugate vaccines (PCVs). DATA SOURCES: Four electronic databases were searched. STUDY SELECTION: We selected all cohorts or case-control studies of IPD and pneumonia in populations who already received PCV (largely 7-valent pneumococcal conjugate vaccine), but not 23-valent pneumococcal polysaccharide, in which authors reported data for children with asthma and in which healthy controls were included, without language restriction. DATA EXTRACTION: Two reviewers independently reviewed all studies. Primary outcomes were occurrence of IPD and pneumonia. Secondary outcomes included mortality, hospital admissions, hospital length of stay, ICU admission, respiratory support, costs, and additional medication use. RESULTS: Five studies met inclusion criteria; of those, 3 retrospective cohorts (∼26 million person-years) and 1 case-control study (N = 3294 children) qualified for the meta-analysis. Children with asthma had 90% higher odds of IPD than healthy controls (odds ratio = 1.90; 95% confidence interval = 1.63-2.11; I(2) = 1.7%). Pneumonia was also more frequent among children with asthma than among controls, and 1 study reported that pneumonia-associated costs increased by asthma severity. LIMITATIONS: None of the identified studies had information of asthma therapy or compliance. CONCLUSIONS: Despite PCV vaccination, children with asthma continue to have a higher risk of IPD than children without asthma. Further research is needed to assess the need for supplemental 23-valent pneumococcal polysaccharide vaccination in children with asthma, regardless of their use of oral steroids.