Acute bacterial meningitis is a severe infection, which leads to persistent neurological deficits in up to 50% of patients, despite optimal medical treatment. Although, the incidence of acute bacterial meningitis has declined in developed countries since the advent of vaccines against Haemophilus influenzae and Streptococcus pneumoniae, this is not yet true for developing countries. Also, the impact of serotype replacement in invasive pneumococcal disease cannot be estimated to date.