Interpretation of response to pneumococcal polysaccharides in patients 2 years of age and older with possible immunodeficiency

PPV-23: 23-valent pneumococcal polysaccharide vaccine.

* The number of serotypes to which the patient is expected to have titers ≥1.3 mcg/mL to be considered adequate is determined by age:

• Age 2 to 5 years – 50% or more of serotypes should be ≥1.3 mcg/mL
• Age 5 years and older – 70% or more should be ≥1.3 mcg/mL

Note that in patients who only received the conjugate pneumococcal vaccine in the past, titers ≥0.35 mcg/mL are adequate to provide protection against invasive pneumococcal disease. Also, if the patient received a conjugate pneumococcal vaccine in the past, then only consider the serotypes that are unique to PPV-23.

¶ Poor immunologic memory is detected by an initially adequate response to PPV-23, which then becomes inadequate within 1 year of vaccination.