Pneumococcal conjugate vaccines reduce myringotomy with tympanostomy tube insertion in young children in Japan

OBJECTIVE: Pneumococcal conjugate vaccines (PCVs) have been reported to reduce the incidence of myringotomy with tympanostomy tube insertion (MTTI) in children. However, little information is available focusing specific ages. We examined the prophylactic efficacy of PCVs on the onset of complex otitis media (ComOM) that requires MTTI. METHOD: From 2011, the public support for PCV7 started with the usual four‐dose schedule and an emergency schedule for 2‐ to 4‐year‐old children in Japan. PCV7 was replaced with PCV13 in 2013. We reviewed the nationwide database obtained from the JMDC Claims Database (https://www.jmdc.co.jp/en/) to examine the MTTI incidence during the era before and after PCV introduction (from 2008 to 2010 and from 2011 to 2017, respectively). Subjects were analyzed by stratified age groups (from 0 to 8 years old) and in subdivided groups of 6 months (from 0 to 35 months old). We compared the MTTI incidence between the groups for each age as well as between those for each calendar year. RESULTS: A significant reduction in the MTTI incidence was detected in the 1‐year‐old children of the PCV era compared to those of the pre‐PCV era. The reduction rates were more prominent in the 12–17 months group as compared to the 18–23 months group (PCV7 p = .005 and PCV13 p = .011, PCV7 p = .014 and PCV13 p = .153, respectively). The significant difference in the 1‐year‐old children continued in six of seven calendar years from 2011 to 2017, whereas no significant reduction was detected in children >3 years old. CONCLUSIONS: The introduction of both PCV7 and PCV13 reduced MTTI incidences in children around 1 year old, and the effects were more prominent during the early half‐periods. Our results support etiological evidence that pneumococcal infection in children aged 1 year and younger might play roles in the pathogenesis of ComOM that requires MTTI.