Houston Researchers Show 20% Of Texans Have Covid Antibodies

The Texas CARES survey gives real-time updates on the pandemic's impact.

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Medical researchers in Houston released preliminary data showing up to 24% of Texas have Covid-19 antibodies. The Texas CARES (Coronavirus Antibody Response Survey) project is a joint effort between UT Health and the Texas Department of State Health Services. This survey, launched only four months ago, is the largest Covid-19 testing database in the United States.

The project aims to enroll a diverse group of 75,000 people age 5-80 to identify the number of Texans who have Covid-19 antibodies and track the disease's progression over time. The data collection assists public officials in making policy decisions by providing a Covid-19 snapshot in real-time.

Texas CARES published preliminary data on the website dashboard showing that 14% to 24% of Texans have COVID-19 antibodies. Data from the population sample estimates that 27% of Hispanic Texans have COVID-19 antibodies as do 29% of Texans younger than 19.

Image CC Txcares dashboard

After exposure to Covid-19, our immune system creates antibodies to help fight disease. Certain specific antibodies appear quickly, while others appear 4-6 weeks after the infection. A positive antibody test is an indicator of a past infection or past exposure. Tracking the number of Texas with positive antibodies can be combined with the number of vaccinated residents to help project a point in time when the state may reach herd immunity.

Participants in the Texas CARES survey are prescreened with a health survey. Then, they are scheduled for blood testing at a local laboratory collection site. Testing centers are located in Houston, Dallas, Austin, San Antonio, Brownsville, and El Paso through partnerships with Clinical Pathology Laboratories (CPL) and The University of Texas System.

Antibody levels are collected over a series of three blood draws over three months, allowing scientists to determine the baseline Covid carrier rate and track antibody conversion over time. Testing Texans over time give scientists insight into the prevalence of Covid-19 exposures and the rate at which residents are developing antibodies.

The current scientific literature indicates that positive antibodies from a natural infection have some degree of immunity. We do not know how long natural immunity lasts or how much protection natural immunity provides against the growing threat of Covid variants. The scientific evidence is clear that natural immunity provides less protection than antibodies from vaccination.

There are three FDA-approved vaccines for Covid-19. The two messenger RNA vaccines from Moderna and Phizer offer 95% protection against Covid-19. The Johnson and Johnson’s Janssen vaccine offers 72% protection against infection and 86% against severe disease. So far, data indicates these vaccines are effective against the variants arising in Texas.

The vaccine rollout is improving across the state. Vaccine hubs have ramped up staff to accommodate the increased demand as Texas expanded the eligibity pool to those 50 years old and older. More than half of all Texas seniors have gotten at least one vaccine dose, and 30 percent are now fully vaccinated. Each day thousands more receive their vaccination.

All three vaccines are highly effective in preventing death.

The Texas CARES project is still looking for participants in Houston and all over the state. Recruitment is targeting people from a variety of backgrounds to increase the diversity of the data set. Currently, 7,622 people have enrolled with a goal of 75,000.

Image CC Txcares dashboard

The Texas CARES project is an opportunity for Texans to pitch in and help. To collect the most accurate information, the survey needs as many participants as possible.

Texans can sign up to participate in the survey here.