COVID-19 variant cases are on the rise in Texas. Here's what you need to know.

Last winter, health experts worried about COVID-19 variants spreading quickly across the state, further overwhelming already crammed intensive care units. While health officials remain concerned about the potential for a wider outbreak fueled by more contagious variants, new case averages, hospitalizations and deaths are still trending down in Texas as the number of people fully vaccinated statewide has passed 25%.

Nationwide, the average weekly number of new COVID-19 cases has dropped in more than half of states as 29% of Americans are now fully vaccinated.

While COVID-19 started out as one strain, it has since spawned dozens of recorded mutations, said Benjamin Neuman, a virologist and professor at Texas A&M University.

New confirmed cases of coronavirus in Texas each day

As of May 3, there are 2.5 million confirmed cases in 254 counties. The average number of cases reported over the past seven days shows how the situation has changed over time by de-emphasizing daily swings. The number of new cases reported drops on weekends, when labs are less likely to report new data to the state.

Source: Texas Department of State Health Services
Credit: The Texas Tribune

Variants are a concern because some spread more easily, may cause severe illness in more people and could be resistant to current treatments for COVID-19, The Texas Tribune reports. Some experts worry that as more mutations pop up, hospitalizations and deaths may rise as well. The U.S. Centers for Disease Control and Prevention says vaccines and other preventive measures like social distancing and mask-wearing should protect people from variants.

Here's what you need to know about COVID-19 variants in Texas:

Which variants are being tracked by the state?

The most dominant strain in Texas and the country is currently the B.1.1.7 variant from the United Kingdom, first detected in the United States in December. The CDC has also listed mutations first discovered in California, South Africa and Brazil as variants of concern. So far in Texas, cases of the five CDC variants of concern have slowly increased since the winter: more than 2,000 variant cases have been reported to the Department of State Health Services as of April 29, though the actual number may be higher, said Jennifer Shuford, the chief state epidemiologist. In early March, Houston became the first city in the state to report at least one case of each variant of concern.

The first variant to be publicly identified and reported out of Texas, the Brazos Valley variant, was discovered by Texas A&M scientists in mid-April. Neuman said they identified three Brazos Valley mutations - BV-1, BV-2 and BV-3 - of which only five cases have been reported.

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Neuman said while BV variants have gotten wide attention, others have been present in the state as well. From a public health standpoint, it's important to keep watching for new variants while case numbers are still low, he said.

"Texas is a gold mine," Neuman said. "The COVID strains we have in Texas are largely unexplored at the moment, and the virus is out there changing and evolving every day, whether we're paying attention to it or not. I would imagine there are quite a few other surprises lurking out there in places where we're just starting to look."

How do they test for variants and how much testing is the state doing?

Checking for COVID-19 mutations starts with the typical PCR or antigen test, usually in the form of nose or mouth swabs - tens of thousands of which are conducted every day in the state. However, not every test gets put through the rigorous genomic sequencing required to find a mutation, which can cost labs around $50 to $100 and on average takes a week or more. Shuford said many universities are sequencing all of their positive tests, but many public health labs prioritize certain types of cases - for example, if an otherwise healthy child were hospitalized with COVID-19 - and do additional random sampling.

Coronavirus test results reported in Texas each day

As of May 2, Texas has administered 28.5 million tests for the coronavirus. We do not know the number of Texans who have gotten a test because some people are tested more than once. The state's tally also does not include pending tests. The average number of tests reported over the past seven days shows how the situation has changed over time by de-emphasizing daily swings.

Source: Texas Department of State Health Services
Credit: The Texas Tribune

More populous regions of the state, like the Dallas-Fort Worth area and southeast Texas, are reporting higher numbers of variant cases - but this could be a reflection of more widespread testing in urban areas.

Houston Methodist's genomics lab has sequenced every positive test from patients in its health care system - roughly 50,000 genomes across 40,000 patients - since the pandemic began, said James Musser, the network's chair of pathology. Musser said Houston Methodist's sequencing effort may be the largest of its kind in the nation and the scale of its sequencing database allows it to have more detailed information about the progression of variants in Texas.

Musser estimated that up to 80% of new COVID-19 cases in Houston Methodist's network have been the UK variant, peaking in April. Higher proportions of variants have not substantially impacted Houston's general case ranges, he said.

Will Texas do more testing for variants in the future?

Shuford said Texas needs to ramp up its genomic sequencing efforts, and once that happens, she said reported variant cases may increase as well.

Currently, the state is waiting on more federal funding to improve testing capacity for variants at public labs and help those labs better report and share data. Whether Texas sees a rise in variants "is going to be dependent on testing, and testing was cut in half by the big freeze at the end of February," Neuman said. "You can't find what you don't test for."

Can vaccination prevent more COVID-19 mutations?

Multiple experts said vaccination is one of the strongest ways to combat the spread of variants and reduce the chance that the virus will keep mutating. But vaccine rates have decreased in Texas, and rates among Black and Hispanic residents have lagged behind white and Asian Texans - in part because of barriers like lack of transportation and distance from vaccine providers.

Because the state is far from herd immunity, transmission of more contagious variants will continue to increase, said Bhavna Lall, assistant professor of adult medicine at the University of Houston College of Medicine. No matter how much progress the United States makes toward testing and vaccinating residents, Lall said global inequities in vaccine distribution will continue to impact everyone, including Texans.

Percent of Texans fully vaccinated

Health experts estimate 75% to 90% of Texans need to achieve immunity to COVID-19 to reach herd immunity. As of May 2, about 27.7% of Texas' 29 million people have been fully vaccinated. One obstacle is vaccines are not approved for children under 16, who make up about 23% of the population.

Source: Texas Department of State Health Services
Credit: The Texas Tribune

Pointing to India's recent crisis - the country's seven-day average of new cases has passed 370,000 while hospitalizations and deaths have skyrocketed - and new variants continuing to pop up worldwide, Lall said until the United States and other developed countries help vaccinate other parts of the world, "we will always be in this pandemic."

"Just because we vaccinate our population in America does not mean that we are going to be safe from other variants that are forming in other countries," Lall said.

Disclosure: Texas A&M University has been a financial supporter of The Texas Tribune, a nonprofit, nonpartisan news organization that is funded in part by donations from members, foundations and corporate sponsors. Financial supporters play no role in the Tribune's journalism. Find a complete list of them here.

The Texas Tribune is a nonprofit, nonpartisan media organization that informs Texans - and engages with them - about public policy, politics, government and statewide issues.

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