Pneumococcal IgG Antibody Responses to 23vPPV in Healthy Controls Using an Automated ELISA

Area of Science:

• Immunology
• Vaccinology
• Clinical Diagnostics

Background:

• Measuring antibody responses to the 23-valent pneumococcal polysaccharide vaccine (23vPPV) is crucial for assessing vaccine efficacy.
• Current gold-standard methods like the World Health Organization ELISA are complex and labor-intensive.
• Interpretation criteria for an adequate response to 23vPPV require further validation.

Purpose of the Study:

• To verify the interpretation criteria for an in-house, automated multi-serotype ELISA used by the diagnostic Immunology Laboratory at The Royal Children's Hospital (RCH).
• To assess the immunogenicity of 23vPPV in both pneumococcal conjugate vaccine (PCV)-naïve adults and PCV-primed children.

Main Methods:

• Healthy adults (n=40) and children (n=22) received 23vPPV immunization.
• Serum samples were collected pre- and post-immunization (28-42 days).
• Samples were analyzed using an automated Tecan Freedom Evo 200 ELISA, with specific criteria defining an adequate antibody response.

Main Results:

• The RCH interpretation criteria were verified, with 97.5% of adults and 100% of children achieving an adequate response.
• A notable finding was that serotypes included in PCV were less immunogenic in PCV-naïve adults, with 30% not meeting response criteria based on these serotypes alone.
• The automated ELISA demonstrated high concordance with established criteria.

Conclusions:

• The study successfully validated the RCH interpretation criteria for their automated multi-serotype pneumococcal ELISA.
• The findings support the use of this automated method for reliable assessment of 23vPPV immunogenicity.
• Consideration of PCV serotype-specific responses is important for interpreting vaccine immunogenicity in different populations.