Table 1.

Classification of pneumococcal serotype failure to vaccination with (PPV) adapted from 13

Phenotype	Memory	Mild	Moderate	Severe
Adults (6–65 years)	Initially > 70% of serotypes > 0·35 µg/ml but response lost in 6 months	Multiple serotypes < 0·35 µg/ml or inability to increase > 70% of serotypes by > twofold	< 70% of serotypes > 0·35 µg/ml but protective titre to 3 or more serotypes	Protective titres to no more than 2 serotypes and titre if present is low (< 0·35 µg/ml)
Children (2–5 years)	Initially > 50% of serotypes > 0·35 µg/ml but response lost in 6 months	Multiple serotypes < 0·35 µg/ml or inability to increase > 70% of serotypes by > twofold	< 50% of serotypes > 0·35 µg/ml but protective titre to 3 or more serotypes	Protective titres to no more than 2 serotypes and titre if present is low (< 0·35 µg/ml)

Mild phenotype assumes pre‐vaccination titres are less than threshold levels (< 0·35 µg/ml) and there may be a response to a second Pneumovax II booster. All phenotypes assume a history of infection. (PPV = pneumococcal polysaccharide vaccine.