Pan-serotype Reduction in Progression of Streptococcus pneumoniae to Otitis Media After Rollout of Pneumococcal Conjugate Vaccines

Clin Infect Dis. 2017 Nov 13;65(11):1853-1861. doi: 10.1093/cid/cix673.


Background: Reductions in otitis media (OM) burden following rollout of pneumococcal conjugate vaccines (PCVs) have exceeded predictions of vaccine impact. In settings with active surveillance, reductions in OM caused by vaccine-targeted pneumococcal serotypes have co-occurred with reductions in OM caused by other pathogens carried in the upper-respiratory tract of children. To understand these changes, we investigated the progression of vaccine-targeted and non-vaccine pneumococcal serotypes from carriage to OM before and after vaccine rollout.

Methods: Nasopharyngeal carriage prevalence of pneumococcus was monitored in prospective studies of Bedouin and Jewish children <3 years old in southern Israel between 2004 and 2016. Incidence of OM necessitating middle-ear fluid culture (predominantly complex OM including recurrent, spontaneously-draining, non-responsive, and chronic cases) was monitored via prospective, population-based active surveillance. We estimated rates of pneumococcal serotype-specific progression from carriage to disease before and after rollout of PCV7/13, measured as OM incidence per carrier. We pooled serotype-specific estimates using Bayesian random-effects models.

Results: On average, rates of progression declined 92% (95% credible interval: 79-97%) and 80% (46-93%) for PCV7/13 serotypes among Bedouin and Jewish children <12 months old, respectively, and 32% (-58-71%) and 61% (-5-86%) among children aged 12-35m. For non-vaccine serotypes, rates of progression among Bedouin and Jewish children aged <12m declined 74% (55-85%) and 43% (4-68%), respectively.

Conclusions: Vaccine-targeted and non-vaccine pneumococcal serotypes showed lower rates of progression to complex OM after rollout of PCV7/13. Early-life OM episodes historically associated with vaccine-serotype pneumococci may impact the susceptibility of children to OM progression.

Keywords: complex otitis media; otitis media; pneumococcal conjugate vaccine; surveillance.

MeSH terms

  • Arabs
  • Bayes Theorem
  • Carrier State / epidemiology
  • Carrier State / microbiology
  • Child, Preschool
  • Disease Progression
  • Female
  • Heptavalent Pneumococcal Conjugate Vaccine / administration & dosage*
  • Heptavalent Pneumococcal Conjugate Vaccine / adverse effects
  • Humans
  • Incidence
  • Infant
  • Israel / epidemiology
  • Male
  • Nasopharynx / microbiology
  • Otitis Media / epidemiology
  • Otitis Media / microbiology*
  • Pneumococcal Infections / epidemiology*
  • Pneumococcal Infections / microbiology
  • Pneumococcal Vaccines / administration & dosage*
  • Pneumococcal Vaccines / adverse effects
  • Population Surveillance
  • Prevalence
  • Prospective Studies
  • Serogroup
  • Streptococcus pneumoniae / immunology
  • Streptococcus pneumoniae / isolation & purification*
  • Streptococcus pneumoniae / physiology
  • Vaccines, Conjugate / administration & dosage


  • 13-valent pneumococcal vaccine
  • Heptavalent Pneumococcal Conjugate Vaccine
  • Pneumococcal Vaccines
  • Vaccines, Conjugate