Assessment of the protective effect of pneumococcal vaccination in preventing meningitis after cochlear implantation

Publisher’s permission requested and denied.Objectives: To examine if a 23-valent pneumococcal capsular polysaccharide vaccine (PPV23) reduces the risk of meningitis in healthy rats after cochlear implantation. Design: Interventional animal study. Interventions: Thirty-six rats (18 immunized and 18 unimmunized) received cochlear implantations and were then infected with Streptococcus pneumoniae via 3 different routes (hematogenous, middle ear, and inner ear) in numbers sufficient to induce meningitis. Results: The rats with implants that received PPV23 were protected from meningitis when the bacteria were delivered via the hematogenous and middle-ear routes (Fisher exact test P<.05). However, the protective effect of the vaccine in the rats with implants was only moderate when the bacteria were inoculated directly into the inner ear. Conclusions: Our animal model clearly demonstrates that immunization can protect healthy rats with a cochlear implant from meningitis caused by a vaccine-covered serotype. This finding supports the notion that all current and future implant recipients should be vaccinated against S pneumoniae