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.