NNDSS Surveillance Materials and Resources

Vaccine–Preventable Disease Morbidity in the United States

A comparison of the morbidity and mortality before and after widespread implementation of national vaccine recommendations for 13 vaccine-preventable diseases for which recommendations were in place prior to 2005.


Roush SW, Murphy TV, Vaccine-Preventable Disease Table Working Group a. Historical Comparisons of Morbidity and Mortality for Vaccine-Preventable Diseases in the United States. JAMA. 2007; 298(19): 2155-2163. Doi:10.1001/jama.298.18.2155.

Presentation Slides

These slides are updated annually to provide vaccine-preventable disease surveillance data for

VPD morbidity slide1: Comparison of 20th Centrury Annual Morbidity and Current Morbidity-Vaccine-Preventable Diseases

Comparison of 20th Century Annual Morbidity and Current Morbidity (slide one [1 page]) updated 2/2/22 (2021 Week 52 NNDSS provisional data as of 1/5/22)

VPD morbidity slide 2 "Comparison of Pre-Vaccine Era Estimated Annual Morbidity with Current Estimate: Vaccine-Preventable Diseases"

Comparison of Pre-Vaccine Era Estimated Annual Morbidity with Current Estimate (slide two [1 page]) updated 2/2/2022


illustration of an open laptop displaying a play icon

For educational materials, see Surveillance Trainings & Videos.

Surveillance of NCIRD Diseases and Conditions in the National Notifiable Diseases Surveillance System (NNDSS)

In cooperation with jurisdiction/state health departments, the National Center for Immunization and Respiratory Diseases (NCIRD) coordinates national surveillance for 20 diseases and conditions in NNDSS, including vaccine-preventable diseases (VPDs) and other respiratory diseases and conditions. CDC is notified by jurisdiction/state health departments of cases of diseases and conditions under national surveillance, as designated by the Council of State and Territorial Epidemiologists (CSTE). NCIRD encourages jurisdiction/state health departments to submit provisional data through NNDSS before completing case investigations; however, cases are included for publication as described in the NNDSS event code list (case status print criteria) approved by CSTE.

CDC publishes NNDSS data weekly in the MMWR and/or CDC WONDER, and yearly in the Annual Summary of Notifiable Diseases. NNDSS data, together with data collected through supplemental surveillance activities, are analyzed by NCIRD staff and are disseminated through surveillance reports, journal manuscripts, MMWR Surveillance Summaries, and other publications.

NCIRD subject matter experts help coordinate surveillance of 20 nationally notifiable conditions, specifically:

Notifiable Conditions and Case Definitions
Congenital rubella syndrome Case definition
COVID-19 Case definition
Diphtheria Case definition
Haemophilus influenzae (invasive disease) Case definition
Influenza-associated pediatric mortality Case definition
Legionellosis Case definition
Measles Case definition
Mumps Case definition
Neisseria meningitidis (meningococcal disease) Case definition
Novel influenza A infections Case definition
Pertussis Case definition
Poliomyelitis (paralytic) Case definition
Poliovirus infections (non-paralytic) Case definition
Psittacosis Case definition
Rubella Case definition
SARS-coronavirus Case definition
Streptococcus pneumoniae (invasive pneumococcal disease) Case definition
Streptococcal toxic shock syndrome Case definition
Tetanus Case definition
Varicella Case definition
To access CSTE position statements for these conditions, refer to the CSTE Position Statement Archive and enter the position statement number listed on the condition’s case definition page (above), title, author, or keyword into the search box. 

Manual for the Surveillance of Vaccine-Preventable Diseases

The Manual for the Surveillance of Vaccine-Preventable Diseases provides current guidelines for those directly involved in surveillance of VPDs, especially personnel at the local and state/territorial (jurisdiction) health departments. For each of the VPDs, the manual includes a chapter describing the importance of rapid case identification; the importance of surveillance; disease reduction goals; case definitions (including clinical description and case classifications); epidemiologically important data to be collected during case investigation; activities for enhancing surveillance; activities for case investigation; and activities for outbreak control. Other chapters include information on surveillance indicators; surveillance data analyses; enhancing surveillance; laboratory support for surveillance; and reporting adverse events following vaccination. In addition, the manual includes a section reserved for insertion of jurisdiction-specific guidance for VPD surveillance, as well as extensive appendices.

Surveillance Indicators

The purpose of vaccine-preventable disease surveillance indicators in the United States is to ensure adequate performance of the essential components of surveillance and case investigation, and to identify components of each that need improvement. Surveillance indicators for selected vaccine-preventable diseases were proposed by CDC and approved by CSTE in 1994. Since then, the indicators have continued to evolve to maximize their usefulness. The CDC currently monitors indicators for measles, mumps, rubella, Haemophilus influenzae, pertussis, meningococcal disease, invasive pneumococcal disease and varicella on a regular basis.

APHL/CDC Vaccine-Preventable Disease Reference Centers

The VPD Reference Centers are four public health laboratories that work closely with the Association of Public Health Laborites (APHL) and CDC to provide quality testing free of charge to other public health laboratories and departments. The VPD Reference Centers are located in California, Minnesota, New York and Wisconsin, and provide testing for measles, mumps, rubella, varicella-zoster, B. pertussis, S. pneumoniae, N. meningiditis, and H. influenzae. For additional information about the testing available at the VPD Reference Centers see APHL’s vaccine-preventable diseases program.

Coordination and Enhancement of Vaccine-Preventable and Respiratory Disease Surveillance

Project support is provided through the Epidemiology and Laboratory Capacity for Infectious Disease (ELC) Cooperative Agreement (CoAg) to enhance vaccine-preventable and respiratory disease surveillance and  coordination (ELC “Project O”). The project focuses on strengthening vaccine-preventable and respiratory disease case-based surveillance and outbreak control, building on the foundation of established surveillance systems (e.g., NNDSS) to provide broader and more representative data.

The ELC “Project O” CoAg has four required activities:

  1. Coordination of NNDSS surveillance for selected vaccine-preventable and respiratory diseases, including the identification of a VPD Surveillance Coordinator.
  2. Enhancement of surveillance for meningococcal disease.
  3. Enhancement of surveillance for varicella.
  4. Establishment/enhancement of surveillance for acute flaccid myelitis.

Optional activities address varicella, pertussis, Haemophilus influenzae, invasive pneumococcal disease, measles, mumps and other vaccine-preventable and respiratory diseases.

Questions about the ELC “Project O” CoAg or requests for project documents should be directed to VPDsurvELC@cdc.gov.

NNDSS Modernization and the Data Modernization Initiative

As a component of the Data Modernization Initiative (DMI), NNDSS modernization activities improve CDC surveillance efforts and also support the goals of the CDC Surveillance Strategy. NMI has three components: 1) development of new HL7 Message Mapping Guides (MMGs), 2) development of the CDC Message Validation, Processing, and Provisioning System (MVPS), and 3) provision of technical assistance (TA) to jurisdictions.

As part of the CDC Surveillance Strategy and NMI, NCIRD has developed a process to support harmonization of variables across the 20 diseases or conditions for which NCIRD provides subject matter expertise. NCIRD considers harmonization to include identification of overlapping and similar concepts across conditions, so that concepts are standardized and harmonized, or a decision is made to retain the concept in a unique format.

OMB-PRA approval has been received for the data included in NNDSS. For details, see Federal Register OMB Package 0920-0728.

Worksheets for Disease/Condition Surveillance

Disease surveillance worksheets have been developed as standard tools to assist jurisdictions with case/outbreak reporting, investigation, and notification. These worksheets are intended as a resource to aid with collection of the surveillance data associated with the HL7 message mapping guides (MMGs). Jurisdictions may modify these worksheets as needed, to best support surveillance needs. The worksheets are not required.

The worksheets listed below are presented both with and without annotations; the annotations show applicable HL7 MMG data element (DE) identifiers for easier mapping into surveillance systems. In addition, the most recent versions (e.g., 2019 for measles) of the worksheets incorporate the additional data elements that are included in the HL7 MMGs, both with and without annotations.

Jurisdictions may use and modify the worksheets to meet their needs, adding and omitting variables as most helpful within the jurisdiction. [Note that the legionella document is a form and therefore may not be modified without OMB approval.] The MMGs, however, are the definitive source for documentation for data elements, valid values, data structure, and other technical issues.

Vaccine Preventable Diseases

See Vaccine Preventable Diseases web page

Congenital Rubella Syndrome (CRS)



Haemophilus influenzae


Meningococcal Disease (more coming soon)



Poliomyelitis (paralytic and nonparalytic)


Streptococcus pneumoniae invasive disease



Non-Vaccine Preventable Diseases



*The legionella document is a form and therefore may not be modified without OMB approval.

Related Links and Resources:

Page last reviewed: June 14, 2022