Validating Georgia’s Vaccine Registry for the COVID-19 2023-2024 Season: True GRITS.

Overview

This validation study assessed the completeness of COVID-19 vaccine reporting to the Georgia Registry of Immunization Transactions and Services (GRITS) during the 2023-2024 vaccination season. Immunization information systems serve as critical infrastructure for public health surveillance and vaccine coverage estimation, but their utility depends on accurate and complete reporting from vaccine providers. The research focused on hospitalized COVID-19 patients in metropolitan Atlanta between October 1, 2023, and December 31, 2023, examining whether vaccination records in the state registry accurately reflected actual vaccination status. The study design employed active surveillance combined with labor-intensive telephone verification to identify potential gaps in registry reporting.

Methods and approach

Investigators conducted active, population-based, and laboratory surveillance across an 8-county metropolitan Atlanta catchment area to identify all residents hospitalized with COVID-19 during the study period. From 2,165 identified hospitalized patients, researchers selected 135 patients through age-stratified random sampling for comprehensive chart reviews. For 86 patients without recorded vaccination on or after September 1, 2023, in the registry, the team initiated follow-up verification procedures. This verification process involved telephone contact with patients or their proxies, pharmacies, and primary care physicians to confirm vaccination status and obtain dates for any unreported vaccinations. The follow-up effort generated 525 telephone calls and consumed approximately 120 person-hours of staff time.

Results

The extensive telephone-based verification process identified only one vaccine dose that had not been recorded in the Georgia Registry of Immunization Transactions and Services. This single unreported dose, discovered after 525 telephone calls and 120 person-hours of follow-up work, represented minimal incompleteness in the registry for the sampled population. The findings indicated that the registry captured nearly all COVID-19 vaccinations administered to hospitalized patients in the metropolitan Atlanta area during the study period.

Implications

The registry demonstrated high reliability as a data source for COVID-19 vaccination status among hospitalized patients in metropolitan Atlanta during the 2023-2024 season. The minimal yield from intensive follow-up procedures suggests that additional verification efforts beyond registry queries may not be cost-effective or necessary for surveillance activities in this setting. These findings support the use of GRITS for public health research and vaccine effectiveness studies without requiring supplemental verification processes. The results provide evidence that provider reporting to the immunization information system achieved substantial completeness for COVID-19 vaccines during this period, validating the registry's utility for epidemiological investigations and vaccine coverage assessments in Georgia.