2021 IISAR Data Participation Rates
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