The CDC is relying on insufficient data from hospitals on COVID-19 breakthrough infections to help with making decisions such as who should get vaccine booster shots, officials with knowledge of the matter told Politico in an Aug. 25 report.
The CDC initially tried to track all infections, from mild to severe, in vaccinated people but in May changed its protocol to focus on the most severe cases. By monitoring only breakthrough cases that result in hospitalization or death, the agency said it hoped to improve the quality of data collected for severe cases that have the greatest clinical and public health importance.
Forty-nine states now regularly send the CDC information on hospitalized breakthrough patients, but more than a dozen state officials told Politico they don't have the bandwidth to match patients' hospital admission data with their immunization records. Those states instead are turning to hospital administrators to report breakthrough infections, which has resulted in data that often leaves out critical details, such as which vaccine a person received and whether they got two shots, the officials said.
These data gaps have raised concerns about how well the Biden administration can identify and respond to changes in the virus's behavior, such as the spread of the delta variant or the performance of vaccines, according to the report.
"I think it would be really challenging [for the CDC] to interpret the results or to interpret the data when you have only some jurisdictions reporting," said Theresa Sokol, lead epidemiologist for Louisiana's public health department, according to the report. "I know that there are some jurisdictions that don't even have access to their vaccination data."
The Louisiana public health department is working closely with the CDC on breakthrough infection studies, the publication reported.