Effect of pneumococcal conjugate vaccination in Uruguay, a middle-income country

In 2008, a 7-valent pneumococcal conjugate vaccine (PCV7) was introduced into the routine childhood immunization program in Uruguay, with a 2+1 schedule. In 2010, PCV13 replaced PCV7, and the same 2+1 schedule was used. The effect of these pneumococcal vaccines on the incidence of invasive pneumococcal infections (IPD) and on serotype distribution was analyzed retrospectively, based on passive national laboratory surveillance. Data from 1,887 IPD isolates from 5 years before and 5 years after PCV7 introduction (7 before and 3 after PCV13 introduction) was examined to assess the incidence rate per 100,000 age-specific population of all IPD, PCV7-serotypes, and PCV13-serotypes associated IPD among children < 2 years and 2 to 4 years old, and patients ≥ 5 years old. Trends of frequency for each serotype were also analyzed. Comparison of pre-vaccination (2003-2007) and post-vaccination (2008-2012) periods showed a significant decrease in IPD incidence among children < 2 years old (IR 68.7 to IR 29.6, p