Invasive Pneumococcal Disease (IPD) is defined as an infection confirmed by the isolation of Streptococcus pneumoniae from a normally sterile site (eg, blood, cerebrospinal fluid, and pleural, joint, or peritoneal fluid but not sputum). Children with pneumococcal infection often present with non-specific symptoms and signs including isolated fever. Certain populations of children are at increased risk of IPD. Children at particularly high risk are those with antibody deficiencies, such as X-link