Invasive pneumococcal diseases in Uruguayan children: comparison between serotype distribution and conjugate vaccine formulations.

An on-going Streptococcus pneumoniae surveillance in Uruguay furnished national information on serotype distribution of isolates from invasive infections in children </=5 years. The adequacy of 7-, 9- and 11-valent conjugate vaccine formulations was evaluated, in comparison with the prevalence of the serotypes causing disease in this target population. From 1994 to 2001, 506 isolates were submitted to the National Reference Laboratory. The heptavalent vaccine would cover 49% of the invasive isolates, while the nonavalent vaccine would potentially prevent 76% of cases. The 11-valent vaccine would increase coverage to 86%. All the serotype/groups of penicillin-resistant isolates are included in the three conjugate vaccine formulations. The available data indicate that the 9- or the 11-valent vaccines, if affordable, are the most suitable formulations for Uruguayan children.