New pneumococcal vaccines for children
- Sheffield Institute for Vaccine Studies, Division of Child Health, University of Sheffield, Sheffield S10 2TH, UK
- Dr Choos.choo{at}sheffield.ac.uk
- Accepted 6 December 2000
Streptococcus pneumoniae remains a major cause of childhood morbidity and mortality. At least 1 million children die of pneumococcal infections each year, mostly in developing countries.1 In addition, pneumococcal resistance to antibiotics such as penicillin is an increasing problem worldwide. The polysaccharide capsule is the main virulence factor of the pneumococcus; 90 different capsular polysaccharide serotypes have been described.2 The prevalence of individual serotypes varies among different age groups and different geographical areas, and changes over time. In this review, we discuss the current epidemiology of paediatric pneumococcal disease in Europe and the potential role of new pneumococcal conjugate vaccines.
Pneumococcal epidemiology
S pneumoniae causes a variety of clinical syndromes, including invasive infections such as bacteraemia and meningitis, as well as pneumonia, and otitis media, with children under 2 years at greatest risk.
INVASIVE DISEASE
The incidence of invasive pneumococcal disease (IPD) per 100 000 children in England and Wales is 39.7 under 1 year of age, 14.5 under 5 years of age, and 6.6 under 15 years of age, based on laboratory reports to the Public Health Laboratory Service.3 4 These rates are comparable to paediatric IPD rates observed in enhanced surveillance studies in the Oxford area4 and South and West England,5 and rates reported from Denmark,6 Switzerland,7 and Finland.8 The proportion of reported IPD isolates in England and Wales showing intermediate or full penicillin resistance increased from 0.3% in 1989 to 2.9% in 1995.9 In other European countries, current rates of penicillin resistance for IPD isolates range from less than 2% in Denmark6 and Germany,10 to more than 30% in Spain11 and Hungary.12
In a meta-analysis of bacterial meningitis outcomes in developed countries,13 S pneumoniaecaused more deaths and neurological sequelae than eitherHaemophilus influenzae orNeisseria meningitidis. …
