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Published on: September 11, 2020
[Serotype 19F pneumococcal meningitis in an imunocompetent infant immunized with heptavalent pneumococcal conjugated
A Isapof1, C Delacourt, P Reinert
1Service de pédiatrie, CHI de Créteil, 40, avenue de Verdun, 94000 Créteil, France. arnaud_isapof@yahoo.com
Insights
Vaccine failure in meningitis occurred despite vaccination due to an immune memory defect. A booster dose is crucial for lasting protection against Streptococcus pneumoniae serotype 19F.
Area of Science:
- Pediatric infectious diseases
- Immunology
- Vaccinology
Context:
- Pneumococcal meningitis remains a concern in vaccinated children.
- Seven cases of vaccine-prevented serotype meningitis occurred in France.
- Four of these cases involved Streptococcus pneumoniae serotype 19F.
Purpose:
- To report a case of pneumococcal meningitis caused by vaccine-relevant serotype 19F in a vaccinated child.
- To highlight potential vaccine failure mechanisms.
- To emphasize the importance of booster vaccination schedules.
Summary:
- A 3-year-old child developed pneumococcal meningitis despite receiving three doses of the 7-valent pneumococcal conjugate vaccine.
- The causative agent was Streptococcus pneumoniae serotype 19F, a serotype included in the vaccine.
- The case demonstrated an immune memory installation defect, suggesting inadequate antibody avidity and protection.
Impact:
- Underscores the necessity of booster doses for sustained protective antibody levels.
- Highlights the unique immunogenicity of Streptococcus pneumoniae serotype 19F.
- Recommends ruling out underlying immune deficits in cases of vaccine failure.
Introduction:
Seven cases of pneumococcal meningitis caused by serotypes covered by the available vaccine occurred in France in vaccinated children, 4 of which were caused by serotype 19F.
Case Report:
A 3-year-old child, who had received 3 doses of the 7-valent pneumococcal conjugate vaccine Prevenar but not the 4th injection, presented with bacterial meningitis after acute media otitis. The identified bacterium was a 19F serotype of Streptococcus pneumoniae.
Comments:
This vaccine failure was characterized by an immune memory installation defect and underscores the necessity of the booster dose of vaccine during the 2nd year of life to acquire rates of protective and lasting antibodies. Serotype 19F of S. pneumoniae is particular since, despite good immunogenecity, it induces antibodies with weak avidity. We describe a case of pneumococcal meningitis caused by 19F serotype S. pneumoniae, which is included in the vaccine, in an immunocompetent child. Such events should be inventoried. They can reveal rates of antibodies that are very weak defenders, in spite of the vaccination, reflecting the absence of implementation of immunizing memory. Furthermore, an underlying immune deficit must be ruled out.
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