Trends in Otitis Media Incidence After Conjugate Pneumococcal Vaccination: A National Observational Study

Abstract

Background: Pneumococcal conjugate vaccine (PCV) was introduced in 2000. The first 7-valent vaccine (PCV7) was followed by a 13-valent vaccine (PCV13) with the same conjugate, and a 10-valent vaccine (PCV10), conjugated to protein D from Haemophilus influenzae. The vaccines offer some protection against pneumococcal acute otitis media (AOM), and, with PCV10, possibly also some protection against H. influenzae AOM. PCV7 was introduced in Sweden in 2009, but from 2010, Swedish counties were free to use either PCV13 or PCV10. The purpose of this study was to investigate the incidence of AOM-related diagnoses and surgical procedures before and after the introduction of PCV in Sweden, but also to compare the areas using PCV13 and PCV10.

Methods: Data showing the number of AOM diagnoses, ventilation tube insertions, myringotomies, acute mastoiditis cases and mastoidectomies between 2005 and 2014 were extracted from the National Board of Health and Welfare database. Yearly national incidences were calculated, and areas using PCV13 and PCV10 were compared.

Results: AOM incidence decreased, both in outpatients (39%) and hospital admissions (42%). Ventilation tube insertions decreased by 18%, and myringotomies by 15%. The decline in outpatient AOM and ventilation tube insertions was more pronounced in areas that used PCV10, but geographical differences were large also before vaccine introduction.

Conclusion: Otitis media-related diagnoses have decreased in Sweden since the introduction of PCV. Though some decreases were more pronounced in areas where PCV10 were used, figures should be interpreted with great caution, because considerable geographical differences were obvious also before vaccine introduction.