Overwhelming infection remains a problem for children who have no spleen either because they were born without one or because they have undergone splenectomy. They are at risk from all encapsulated bacterial pathogens but more than half of invasive infections in these children are caused by Streptococcus pneumoniae. Data on invasive pneumococcal infections have been collected from eight children’s hospitals in the United States since 1993 (Gordon E Schutze and colleagues. …