Up to 22 percent of Houston residents have COVID-19 antibodies, according to a study by the Texas Department of Health Services and the University of Texas Health Sciences Center in Houston researchers.
A four-month study of patients across the state, called Texas CARES, found antibodies in 14 to 24 percent of those tested.
“If you want to start measuring the frequency of COVID-19 in our population, looking at antibodies is one of the best ways to do that,” said Eric Boerwinkle, dean of the School of Public Health at UTHealth.
The presence of antibodies – proteins in a patient’s immune system that fight infections – shows researchers that these individuals have contracted the virus in recent months. El Paso led the main cities with 29 percent of surveyed residents testing positive for COVID-19 antibodies, followed by Dallas with 27 percent, San Antonio with 26 percent, Houston with 22 percent, Brownsville with 20 percent and Austin with 15 percent.
The researchers gave nearly 7,000 participants a questionnaire about their health and several blood samples to assess their immune systems, and also evaluated more than 78,000 unidentified blood samples from clinics across the state. The research assesses how long the immunity and antibody responses of asymptomatic individuals last.
Preliminary data indicates that 27 percent of the Hispanic population in Texas and 29 percent of Texans 19 years and younger have COVID-19 antibodies.
The frequency of antibodies in youth is alarming, said Boerwinkle. Many children never know that they are carrying SARS-CoV-2, the virus that causes COVID.
“We are very lucky that young people do not get sick as often when they are exposed to the virus,” he said. “At the moment, we don’t have an approved vaccine for children. We need to be careful, though, since we don’t understand why some children have serious COVID effects. “
The first reports show COVID-19 antibodies living in the body for up to eight months after infection, according to Science, a peer-reviewed medical publication. Proteins are critical to understanding infection rates and risk factors for the virus.
Texas researchers said it was too early to determine how long antibodies last based on the state study, but said it was rare to find patients who tested positive for protein and tested negative on a second blood sample.
“The Texas CARES study is a cutting edge science that will provide valuable information to enable Texas to formulate public health strategies that will ultimately defeat the pandemic,” said Dr. John Hellerstedt, commissioner of the Texas Department of Health Services , in a statement.
Infusions of antibodies from people who have recovered from COVID-19 are part of the treatment strategies of some doctors. Several monoclonal antibody drugs are now available under emergency use authorization for use in patients who are at risk for serious complications.
The study, which began in October, aims to enroll 75,000 people. People are eligible to participate in the study regardless of whether they have been tested for COVID-19, but those with active infections must wait until they have recovered to enter.
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