A closer look at breakthrough COVID-19 cases in vaccinated residents in Houston-area

HOUSTON – In this latest wave of the COVID-19 pandemic, breakthrough cases in people who have been fully vaccinated are getting a lot of attention, but doctors say they are extremely rare.

“They tend to be seen in folks who for whatever reason can’t mount a great immune response, like people who are elderly, immunocompromised, folks on dialysis folks on chemotherapy,” said Dr. Linda Yancey, infectious disease expert at Memorial Hermann.

Local health departments say they identify breakthrough cases by cross-checking positive lab results with Texas Health Trace the state’s COVID-19 disease reporting tool and ImmTrac, the state’s immunization database.

KPRC 2 gathered the following data on breakthrough cases in counties across the Houston area.

- Houston: 2,146 breakthrough cases out of 1,510,588 fully vaccinated people. A breakthrough rate of 0.142%

- Harris County: 2,093 breakthrough cases, less than 1% of the fully vaccinated community.

- Fort Bend County: 559 breakthrough cases

- Galveston County: 388 breakthrough cases

- Brazoria County: 53 breakthrough cases out of 162,765 fully vaccinated people.

A spokesperson for the Montgomery County Hospital District told KPRC 2 they were unable to release an exact number of breakthrough cases “due to the current number of positive test results, but the number is a very small percentage of those who have been fully vaccinated.”

Most of the agencies KPRC 2 has spoken to are relying on the state’s vaccine database to verify a positive patient’s vaccine status.