Thirdly, the identification of radiological pneumonia cases that have an elevated CRP [48], and have either heavy nasopharyngeal carriage, or carriage of pneumonia-associated serotypes, will identify a subgroup that is more likely to be pneumococcal in origin and may thus be expected to decline in incidence more sharply than the total radiological incidence with the introduction of an effective PCV. The gene discussed is CRP; the disease is susceptibility to pneumonia measurement.