Surveillance and Reporting

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Data from two surveillance systems show a dramatic impact on decreasing invasive pneumococcal disease (IPD) rates in the United States following introduction of pneumococcal conjugate vaccines.


IPD, like meningitis and bloodstream infections, is a reportable condition in all states. CDC tracks IPD through two systems: National Notifiable Diseases Surveillance System (NNDSS) and Active Bacterial Core surveillance (ABCs).

CDC does not track non-invasive pneumococcal disease, like ear and sinus infections, through either surveillance system.

National Notifiable Diseases Surveillance System

State health departments report IPD to CDC through NNDSS. Health departments should report both suspected and confirmed cases.

Active Bacterial Core surveillance

Some regions in the United States also track IPD cases through ABCs. ABCs is an active, laboratory- and population-based surveillance system for invasive bacterial pathogens of public health importance. Researchers and public health professionals use ABCs data to track disease trends, including the decline in pneumococcal disease following the introduction of the pediatric pneumococcal conjugate vaccine.

Bact Facts Interactive

Analyze and visualize ABCs S. pneumoniae data using Bact Facts Interactive.

magnifying glass with bacteria symbol


IPD surveillance in the United States began in 1998. IPD dramatically declined in children and adults after the United States began using pneumococcal conjugate vaccines (PCVs).

CDC first recommended

  • PCV7: 2000 in children
  • PCV13: 2010 in children; 2012 in adults with risk conditions; 2014 in adults 65 years or older
  • PCV15: 2021 in adults; 2022 in children
  • PCV20: 2021 in adults; 2023 in children

Childhood vaccination and disease trends

From 1998 through 2021, IPD rates among children less than 5 years old decreased by

  • 95% overall
  • 99% for disease caused by serotypes covered by PCV13

IPD caused by the serotypes covered by 23-valent pneumococcal polysaccharide vaccine (PPSV23) also declined during this time. However, these reductions were due to declines in IPD caused by serotypes in common with PCV13. PPSV23 has been available since 1984.

Adult vaccination and disease trends

Declines in IPD were seen as early as 2001 among adults. These declines were due to use of pneumococcal conjugate vaccines in children through community or herd immunity.