Prevention of acute otitis media (AOM), and especially recurrence and biofilm formation, by pneumococcal conjugate vaccines has been hypothesized to be due to prevention of early episodes triggering the vicious cycle. We tested the specific role of vaccine-type pneumococcal AOM in this hypothesis.Methods:
In the phase III randomized, double-blind Finnish otitis media Vaccine Trial conducted in 1995–1999, children received pneumococcal conjugate vaccine 7 or hepatitis B vaccine as control at 2, 4, 6, and 12 months of age and were followed for AOM. Myringotomy with middle ear fluid aspiration was performed in AOM, and samples were cultured. We compared control-vaccinated children with confirmed vaccine-type or 6A-AOM with those with AOM due to other confirmed etiology within 2–6 months of age (early AOM) and followed for subsequent AOM from 6–24 months of age.Results:
Eight hundred thirty-one children were enrolled in the Finnish otitis media control arm. Before 6 months of age, 34 children experienced vaccine-type–AOM, and 40 children experienced AOM of other bacterial etiology. The subsequent AOM incidences were 1.9 (95% CI, 1.5–2.4) and 2.1 (1.7–2.5) in these subgroups, respectively. However, the subsequent incidences were lower if no bacteria were detected at AOM (1.5, 1.2–1.8) or if there was no early AOM (1.1, 1.1–1.2).Conclusions:
Early vaccine-type AOM was not associated with a higher risk of subsequent AOM compared with AOM due to other confirmed bacterial etiology. These data do not support any specific role of vaccine-type pneumococcus in the hypothesis.