Vaccines May Be Responsible for Drop in Ear Infection Rates

The introduction of pneumococcal conjugate vaccines are likely responsible for the declining incidence of ear infections over the last 30 years, according to the results of a recent study¹.In order to examine the epidemiology of acute otitis media (AOM) during the pneumococcal conjugate vaccines (PCVs) 7 and 13 era, researchers conducted a prospective study of 615 children, aged 6 to 26 months, from June 2006 to June 2016. Nasopharyngeal and blood samples were taken at regular intervals from 6 to 36 months, and at every AOM episode.

By year 1 of age, 23% of participants had experienced 1 or more episodes of AOM. By 3 years of age, 60% had experienced 1 or more episodes of AOM, and 24% had experienced 3 or more episodes. These incidence rates were significantly lower than those reported by Teele, et al, in a 1989 study of AOM², in which 80% of children had 1 or more episodes and 40% had 3 or more episodes by 3 years of age.

Male sex, non-Hispanic white race, family history of recurrent AOM, day care attendance, and early occurrence of AOM were all found to be associated with significantly increased risk of AOM. Further, the proportion of Streptococcus pneumoniae, Haemophilus influenzae, and Moraxella catarrhalis causing AOM changed dynamically over the past decade, the researchers reported.

“The epidemiology of AOM has undergone shifts over the past 30 years, especially since the introduction of PCVs. Because the risk factors for AOM we identify in this study are predominantly similar to those described by Teele et al, we conclude that much of the shift in otopathogen prevalence can be attributed to the influence of the vaccine and changes in diagnostic criteria for AOM versus otitis media with effusion.”

1. Kaur R, Morris M, Pichicher ME. Epidemiology of acute otitis media in the postpneumococcal conjugate vaccine era [published online August 7, 2017]. Pediatrics. doi: 10.1542/peds.2017-0181.

2. Teele DW, Klein JO, Rosner B. Epidemiology of otitis media during the first seven years of life in children in greater Boston: a prospective, cohort study. J Infect Dis. 1989;160(1):83–94pmid:2732519