Anaphylaxis to the 23-valent pneumococcal vaccine in child: a case-control study based on immediate responses in skin...

Area of Science:

• Immunology
• Allergy and Clinical Immunology
• Vaccinology

Background:

• The 23-valent pneumococcal vaccine is generally safe, but severe hypersensitivity reactions can occur.
• Accurate diagnosis of vaccine hypersensitivity is crucial for patient management and future vaccination strategies.

Observation:

• A child experiencing severe anaphylaxis post-pneumococcal vaccination underwent skin testing (prick and intradermal) and a radioallergosorbent test (RAST) using pneumococcal vaccine and phenol.
• Ten control children (one with uneventful vaccination, nine unvaccinated) were also tested.
• Skin tests and RAST with the vaccine were positive in the anaphylactic child and negative in most controls.

Findings:

• Positive skin tests and RAST with pneumococcal vaccine in the patient suggest IgE-mediated hypersensitivity.
• A non-vaccinated child showed a weakly positive intradermal test with the vaccine but a negative RAST.
• All subjects had negative skin tests and RAST with phenol, ruling out phenol as a sensitizer.

Implications:

• Immediate hypersensitivity reactions to pneumococcal vaccine can be diagnosed using skin tests and specific IgE determination.
• These diagnostic tools demonstrate good value in identifying children with suspected IgE-dependent hypersensitivity to pneumococcal vaccines.
• Findings support the utility of allergy testing in evaluating severe adverse events following pneumococcal vaccination.