No abstract

SUMMARY Background In 2000, 7-valent pneumococcal conjugate vaccine (PCV7) was introduced in the U.S. and resulted in dramatic reductions in invasive pneumococcal disease (IPD) and modest increases in non-PCV7-type IPD. In 2010, a 13-valent pneumococcal conjugate vaccine (PCV13) replaced PCV7 in the U.S. immunization schedule. We evaluated the effect of PCV13 use in children on IPD in children and adults in the U.S. Methods We used laboratory- and population-based data on incidence of IPD from CDC’s Emerging Infections Program / Active Bacterial Core surveillance in a time-series model to estimate the impact of vaccination. Cases of IPD during July 2004–June 2013 were classified as being caused by the PCV13 serotypes against which PCV7 has no effect (PCV13/nonPCV7). Findings Compared with incidence expected among children <5 years old if PCV7 alone had been continued, incidence of IPD overall and IPD caused by PCV13/nonPCV7 serotypes declined by 64% (95% interval estimate [IE] 59–68 %) and 93% (95%IE 91–94), respectively, by July 2012–June 2013. Among adults, incidence of IPD overall and PCV13/nonPCV7-type IPD also declined by 12–32% and 58–72%, respectively, depending on age. In all age groups, reductions were driven principally by changes in incidence of serotypes 19A and 7F. We estimate that over 30,000 cases of IPD and 3,000 deaths were averted in the first 3 years following PCV13 introduction. Interpretation PCV13 has reduced IPD among all ages when used routinely in children in the U.S. Serotypes 19A and 7F, which emerged after PCV7 introduction, have been effectively controlled.

The rates of bacterial meningitis have decreased since 1998, but the disease still often results in death. With the success of pneumococcal and Hib conjugate vaccines in reducing the risk of meningitis among young children, the burden of bacterial meningitis is now borne more by older adults. (Funded by the Emerging Infections Programs, Centers for Disease Control and Prevention.).

Multidrug-resistant pneumococci are common and are increasing. Because a limited number of serotypes account for most infections with drug-resistant strains, the new conjugate vaccines offer protection against most drug-resistant strains of S. pneumoniae.