Information on 2021 IISAR Data Participation Rates

At a glance

Review 2021 child and adolescent IISAR data participation rates by U.S. states.

Overview

Child, adolescent, and adult participation rates in IIS are reported for the 2020 IISAR to monitor progress toward Healthy People 2020 objectives and program initiatives. For a discussion on the calculation and reporting of provider site participation rates in IIS, please see the 2012 Immunization Information System progress report in Morbidity and Mortality Weekly Report.

2021 CHILD Participation Table and Map

Percentage of U.S. Children < 6 years with 2+ Immunizations in IIS

Percentage of children aged <6 years participating in an immunization information system (IIS) in the United States (including all 50 states, five cities, and the District of Columbia, and eight territories) in 2021.

National coverage: 98% (excluding territories)

Map of this data (printable version) [1 page]

State/City Percentage
Alabama 81.0%
Alaska 76.9%
Arizona 103.8%
Arkansas 101.7%
California 97.6%
Chicago, IL 100.1%
Colorado 105.1%
Connecticut 95.9%
DC 91.4%
Delaware 104.0%
Florida 91.2%
Georgia 104.2%
Hawaii 63.3%
Houston, TX 143.6%
Idaho 95.3%
Illinois* 95.1%
Indiana 98.7%
Iowa 101.4%
Kansas 90.0%
Kentucky 98.6%
Louisiana 105.9%
Maine 98.4%
Maryland 98.5%
Massachusetts 106.0%
Michigan 96.3%
Minnesota 96.7%
Mississippi 105.5%
Missouri 81.6%
Montana 94.6%
Nebraska 96.3%
Nevada 101.0%
New Hampshire 37.1%
New Jersey 94.4%
New Mexico 100.7%
New York* 100.4%
New York City, NY 100.7%
North Carolina 103.8%
North Dakota 95.9%
Ohio 93.8%
Oklahoma 91.3%
Oregon 98.7%
Pennsylvania* 89.6%
Philadelphia, PA 108.0%
Rhode Island 100.0%
San Antonio, TX 95.1%
South Carolina 107.2%
South Dakota 97.5%
Tennessee 99.2%
Texas* 101.9%
Utah 101.5%
Vermont 102.1%
Virginia 104.9%
Washington 99.5%
West Virginia 94.5%
Wisconsin 97.1%
Wyoming 103.7%

Territories Percentage
American Samoa 116.5%
Guam 43.6%
Marshall Islands 63.1%
Federated States of Micronesia 106.8%
Northern Mariana Islands 89.0%
Palau 17.5%
Puerto Rico 90.0%
Virgin Islands 60.4%

Footnotes

* City-based IIS participation rates are reported separately from their respective states; state rates do not include city data in their values.

Reported annual fluctuations in child participation may be due to programmatic and/or technical changes to the immunization information system. The denominator used to calculate child participation numbers are drawn from the 2021 Census estimates for each state and city.

Source: Immunization Information System Annual Report, CY2021

2021 ADOLESCENT Participation Table and Map

Percentage of U.S. Adolescents 11-17 years with 2+ Adolescent Immunizations in IIS

Percentage of adolescents aged 11-17 years participating in an immunization information system (IIS) in the United States (including all 50 states, five cities, and the District of Columbia, and eight territories) 2021.

National coverage: 86% (excluding territories)

Map of this data (printable version) [1 page]

State/City Percentage
Alabama 77.1%
Alaska 78.8%
Arizona 88.9%
Arkansas 96.8%
California 81.2%
Chicago, IL 74.9%
Colorado 87.7%
Connecticut 72.3%
DC 115.6%
Delaware 96.8%
Florida 73.8%
Georgia 96.8%
Hawaii 61.8%
Houston, TX 118.0%
Idaho 79.9%
Illinois* 100.0%
Indiana 90.4%
Iowa 88.2%
Kansas 78.6%
Kentucky 89.0%
Louisiana 96.8%
Maine 115.0%
Maryland 86.1%
Massachusetts 96.3%
Michigan 86.9%
Minnesota 84.9%
Mississippi 76.0%
Missouri 71.2%
Montana 81.8%
Nebraska 86.0%
Nevada 91.1%
New Hampshire 46.5%
New Jersey 78.4%
New Mexico 96.2%
New York* 98.3%
New York City, NY 111.9%
North Carolina 89.5%
North Dakota 85.3%
Ohio 81.7%
Oklahoma 77.2%
Oregon 86.4%
Pennsylvania* 84.1%
Philadelphia, PA 104.4%
Rhode Island 90.6%
San Antonio, TX 69.5%
South Carolina 86.7%
South Dakota 92.1%
Tennessee 83.4%
Texas* 78.8%
Utah 95.5%
Vermont 93.4%
Virginia 108.0%
Washington 84.2%
West Virginia 72.6%
Wisconsin 86.4%
Wyoming 75.4%

Territories Percentage
American Samoa 122.1%
Guam 71.7%
Marshall Islands 60.0%
Federated States of Micronesia 62.8%
Northern Mariana Islands 89.8%
Palau 53.2%
Puerto Rico 134.9%
Virgin Islands 56.4%

Footnotes

* City-based IIS participation rates are reported separately from their respective states; state rates do not include city data in their values.

Reported annual fluctuations in child participation may be due to programmatic and/or technical changes to the immunization information system. The denominator used to calculate child participation numbers are drawn from the 2021 Census estimates for each state and city.

Source: Immunization Information System Annual Report, CY2021

2021 ADULT Participation Table and Map

Percentage of U.S. Adults 19+ years with 1+ Adult Immunizations in IIS

Percentage of adults aged 19+ years participating in an immunization information system (IIS) in the United States (including all 50 states, five cities, and the District of Columbia, and eight territories) in 2021.

National coverage: 89% (excluding territories)

Map of this data (printable version) [1 page]

State/City Percentage
Alabama 51.4%
Alaska 95.5%
Arizona 103.3%
Arkansas 117.0%
California 78.5%
Chicago, IL 79.2%
Colorado 92.1%
Connecticut 91.9%
DC 48.6%
Delaware 112.2%
Florida 120.9%
Georgia 100.5%
Hawaii 61.8%
Houston, TX 17.6%
Idaho 96.5%
Illinois* 104.6%
Indiana 89.0%
Iowa 95.0%
Kansas 109.1%
Kentucky 96.3%
Louisiana 101.3%
Maine 99.0%
Maryland 80.1%
Massachusetts 107.3%
Michigan 102.7%
Minnesota 113.3%
Mississippi 97.5%
Missouri 90.6%
Montana 108.1%
Nebraska 109.7%
Nevada 125.1%
New Hampshire 73.4%
New Jersey 16.1%
New Mexico 118.5%
New York* 95.3%
New York City, NY 110.2%
North Carolina 59.1%
North Dakota 99.5%
Ohio 97.1%
Oklahoma 93.9%
Oregon 121.5%
Pennsylvania* 108.9%
Philadelphia, PA 114.7%
Rhode Island 86.9%
San Antonio, TX 16.6%
South Carolina 100.0%
South Dakota 116.1%
Tennessee 98.0%
Texas* 14.0%
Utah 109.8%
Vermont 112.2%
Virginia 128.0%
Washington 115.1%
West Virginia 71.3%
Wisconsin 111.5%
Wyoming 108.6%

Territories Percentage
American Samoa 147.2%
Guam 112.8%
Marshall Islands 75.8%
Federated States of Micronesia 108.1%
Northern Mariana Islands 109.8%
Palau 79.8%
Puerto Rico 59.7%
Virgin Islands 72.7%

Footnotes

* City-based IIS participation rates are reported separately from their respective states; state rates do not include city data in their values.

Reported annual fluctuations in child participation may be due to programmatic and/or technical changes to the immunization information system. The denominator used to calculate child participation numbers are drawn from the 2021 Census estimates for each state and city.

Source: Immunization Information System Annual Report, CY2021