Summary

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Introduction

Immunization is the best way to prevent illness and severe outcomes from vaccine-preventable diseases and prevent them from spreading in the community. The Advisory Committee on Immunization Practices (ACIP) provides a vaccine schedule¹ to achieve protection against 14 diseases by 24 months of age. These include diphtheria, tetanus, acellular pertussis, measles, mumps, rubella, Haemophilus influenzae type b, rotavirus, hepatitis B, hepatitis A, varicella, polio, pneumococcal disease, and influenza. This report summarizes immunization coverage for children who were 19 through 35 months old in the third quarter of 2023.

Methods

All immunization records and demographic data for children born between October 01, 2020 and February 28, 2022 were obtained from the Georgia Registry of Immunization Transactions and Services (GRITS). Data cleaning removed records if they contained no childhood vaccines, were out-of-state, duplicated, created for testing, or created as a placeholder at birth, or if a child died, resulting in 186,623 records. Each immunization record was evaluated using the ACIP catch-up schedule. The catch-up schedule provides the minimum age and the shortest acceptable interval between immunizations. This allows identification of childredn who were vaccinated appropriately but outside the recommended schedule due to missed vaccines, travel, contraindications, or other unknown reasons. If all doses of a vaccine were correctly administered by 35 months, the child was considered up-to-date on (or covered by) that vaccine.

The 19-35 month age range was selected to match the ages sampled by CDC’s National Immunization Survey (NIS-Child)².

Coverage was calculated for each vaccine individually and for the 7-vaccine series, which includes:

• 4 diphtheria, tetanus, acellular pertussis (DTaP) doses,

• 3 inactivated polio virus (IPV) doses,

• 1 measles, mumps, rubella (MMR) dose,

• 3 Haemophilus influenzae type b (Hib) doses,

• 3 hepatitis B (HepB) doses,

• 1 varicella dose, and

• 4 pneumococcal conjugate vaccine (PCV) doses.

Coverage was further examined by race, ethnicity, age, insurance status, district, and county.

Key Findings

Overall, Georgia’s immunization coverage for the complete 7-vaccine series was 79.6%. By individual vaccines, coverage was highest for pneumococcal conjugate vaccine (PCV) at 93.0% and lowest for influenza (flu) at 35.3%. Coverage for the complete 7-vaccine series was highest among American Indian or Alaska Native (84.1%) children by race; Not Hispanic or Latino (80.6%) children by ethnicity; children aged 19 through 24 months (79.7%); and children with multiple insurance types (84.1%). Coverage for the complete 7-vaccine series was lowest among children with unknown race (69.6%); children with unknown ethnicity (71.9%); children aged 25 through 35 months (79.6%); and children with insurance that did not cover vaccines (44.7%).

Limitations

Some immunization records have multiple addresses associated with them. In these cases, the first complete Georgia address was used to assign county of residence. Children may not have received their vaccines at only one address or at the address selected. In cases where there was no address, the child was assumed to be a Georgia resident and county was left as “unknown.”

The number of records assigned to a county based on GRITS address may be higher or lower than the expected population of a county based on 2023 census data. Counties bordering other states may have children who see providers out-of-state. Counties with high population immigration or emigration (e.g., counties with military bases) may appear to have lower coverage as children more frequently leave before their vaccines are completed.

Additionally, pockets of high or low coverage within or across multiple counties may be obscured by a county-level analysis.

Due to the volume of records (186,623 records), it is not feasible to individually determine correct addresses, and therefore county- and district-level coverage are estimates.

Differences from Past Studies

Previous child immunization studies used a retrospective cohort research design where children who turned two in January were sampled from each district. Identifying information was collected from electronic birth records and vaccination history was collected primarily from GRITS. If the child’s record was not up-to-date, local public health staff contacted parents, guardians, and providers to obtain any missing immunization history data.

Footnotes

¹ https://www.cdc.gov/vaccines/hcp/imz-schedules/child-adolescent-age.html

² https://www.cdc.gov/nis/about/index.html

Interacting with this Report:

There are two tabs beside the “Summary.” The “Report Sections Drop-Down” tab allows navigation to different data tables. The “Maps” tab allows navigation to different county-level maps of vaccination coverage. The bar graph can be enlarged by clicking and dragging over an area then reset by double clicking. Data tables can be copied onto the clipboard, printed, or downloaded as a .csv file, an Excel file, or a PDF with their respective buttons. The search bar allows filtering data in large tables. For example, typing “1-1” in the search bar and pressing the enter key will show any rows for public health district 1-1.

Georgia Totals

Data by Race

Data by Ethnicity

Data by Age

Data by Insurance Coverage

Data by District

Data by County

7-Vaccine Series

DTaP

HepA

HepB

HiB

IPV

MMR

PCV

Rotavirus

Varicella

Influenza