By early July, the delta variant of the novel coronavirus had surpassed all others to become the dominant strain in the U.S. 

This variant, along with relaxed social distancing, has helped spur another uptick in COVID-19 cases in Tarrant County, Texas and across the country. But despite reports of its highly contagious nature, infectious disease epidemiologist Diana Cervantes said delta isn’t as nefarious as it may seem. 

“I think sometimes people think … we’re kind of at the mercy of this variant,” said Cervantes, who’s also an assistant professor at The University of North Texas Health Science Center’s School of Public Health. “But that’s not the case.”

The same precautions that worked against other variants — like physical distancing and vaccines — work against this one, she said. And the same people who were more vulnerable to other variants are vulnerable to this one. 

Here’s what we know about the variant and what it might mean for you and your family.

What is the delta variant? 

The delta variant is a different version of the original SARS-CoV-2 virus that causes the disease COVID-19. As a virus spreads, more versions like this one emerge. 

“The whole purpose of any virus is to make more and more of itself,” Cervantes said. “That’s its one goal — the one reason it exists.”

The more a virus adapts, the more likely it will deviate from the original. These deviations produce different versions, or variants, of the original virus. The variants don’t always meaningfully change how the virus navigates, but some can make it more or less effective at spreading.

How does the delta variant differ from other variants? 

The delta variant has been described as the most contagious strain thus far. However, those messages dilute the complexity of what makes something “contagious,” Cervantes said.

“‘Contagious’ is really more about the person,” she said. “‘Contagious’ is about a person’s ability to directly pass that virus to another person when they are infected.” It can vary by how the virus interacts with their body and how a person spends their time.

In other words, the delta variant may be better at infecting a person’s cells and multiplying than other variants. But the variant itself is only one part of what Cervantes calls the “transmission triangle:” a person, the environment and the virus. 

For example, a person who’s fully vaccinated and contracts a mild or even asymptomatic case of COVID-19 from the delta variant may be more contagious to other people if they live or work in a group setting like a nursing home than an unvaccinated person who contracts COVID-19 from the delta variant, is quickly identified, has no close contacts and isolates alone. 

This means people can adjust their behavior to protect themselves and their family from the delta variant and others. The best way to do so, Cervantes said, is to get the vaccine. 

“Several studies have now shown that the vaccines are highly effective at reducing spread and disease from COVID-19,” she said. “And it’s exactly what we are seeing out in the real world as well.” 

For some people, though, the vaccine isn’t enough. 

“The vaccine is great, but it’s not magic,” she said. “It can’t undo a general weakened state of health, and it can’t undo a lot of contact with people who are infected.” 

That means when Cervantes, who’s vaccinated, is in a crowded or cramped space, she chooses to wear a mask and limit her time in that space. Her decision stems in part from concern for her circle of people. She’s the primary caretaker for her 86-year-old mother. If her mother, who’s vaccinated, were to contract COVID-19, she’d likely be protected from severe symptoms, but her age still makes her more vulnerable than her daughter might be. 

Cervantes’ own decision to mask up precedes new CDC guidance, released Tuesday, recommending that vaccinated people wear masks indoors in places where community transmission is substantial or high, as in Tarrant County. 

Is the delta variant in Tarrant County?

Yes, and it probably became the dominant variant here over the last few weeks, according to Russ Jones, chief epidemiologist at Tarrant County Public Health. 

But we can’t know how many local infections came from the delta variant. That’s partly because not every person with COVID-19 gets tested, and determining which variant caused which infection requires a special “genome sequencing” process in addition to the initial test. 

“The virus is like a book,” Cervantes said. “And you think of words that make up a book.  Sequencing is looking at every single letter and every single word within a book.”

Tarrant County’s health department sends some positive COVID-19 cases to the state health department for sequencing, Jones said. The process requires more equipment and staff than the local department can spare, and it takes time. 

As of last week, the state health department had recorded only seven COVID-19 cases that stemmed from the delta variant within a small sample of positive cases in North Central Texas. That’s not even 2% of the 451 samples taken from the region, which includes Tarrant and Dallas counties. It’s also only a slight increase, about 0.2 percentage-points, from the same numbers in mid-June. According to their dashboard, the alpha variant, which was first documented in the United Kingdom in September 2020, still makes up more than 93% of positive cases in North Central Texas. 

But those numbers are a month or two behind, Cervantes said. And, as the website warns, labs sequence only a small number of positive COVID-19 cases — so these numbers are an undercount. 

But the prominence of the delta variant isn’t the only problem.

“The delta variant alone is not causing this increasing number of cases. It’s because, too, people are out and about like they were pre-COVID,” Cervantes said. “And when you’re out and about, even if you’re vaccinated, you can still get infected, or if you’re not vaccinated, you (can) definitely get infected. You’re just going to see more cases. It doesn’t matter what the variant is.”

How could the delta variant affect me? 

Vaccinated or not, people may still contract COVID-19 from the delta variant. If they do, they’re still able to spread the virus to people around them, which is why Cervantes recommends continued caution regardless of vaccination status, especially for people who are more vulnerable to developing severe disease if they get infected. 

However, a fully vaccinated person with COVID-19 may experience mild or no symptoms and will most likely be protected from hospitalization and death. For example, two doses of the Pfizer vaccine are 88% effective at preventing a symptomatic case of COVID-19 caused by the delta variant, according to a study published last week in the New England Journal of Medicine. 

Unvaccinated people don’t have that protection. If they contract COVID-19 from the delta variant, they may experience a variety of severe effects, including heart inflammation and depression, Jones, with the county health department, said.

“It sets you back, and it’s not just the flu two-week thing for some people. It’s months,” he said. “So, you don’t want to get sick. You want to get a free vaccine.”

The vaccine may decrease a person’s risk of contracting long COVID, a condition that affects some people with symptoms for more than four weeks and, sometimes, for months, after the initial infection. A vaccine may also help alleviate the symptoms of a person with long COVID, Cervantes said. 

How could the delta variant affect Tarrant County?

The more the delta variant spreads, the more COVID-19 infections can cripple the health system in Tarrant County. 

This week, more than 450 people with COVID-19 are in Tarrant County hospital beds, according to the county health department’s website. That number has been increasing since early June, when only about 80 people with COVID-19 were in a hospital bed. That’s going on a 500% increase in less than two months. And as of Tuesday, 86% of local hospital beds were full. 

The increasing number of hospitalized people may be in part because the Tarrant County vaccination rate — 48% this week — is too low, Jones said. As cases increase, more people will be hospitalized. 

“Once a system fails or is overwhelmed, that’s when the disaster starts, things pile up,” he said. “Other things collapse.”

Finally, why is this variant called delta?

In early June, the World Health Organization published a naming scheme for viruses based on letters in the Greek alphabet. Variants dangerous enough to make it on the WHO’s watchlist as a “variant of interest” or the more threatening “variant of concern” receive a letter.

The delta variant, also known as B.1.617.2, was first documented in India in October 2020. By April 2021, the WHO considered it a variant of interest. By May, it was a variant of concern. 

This week, it’s one of four variants of concern on the WHO’s list. More will come, Cervantes said.

“There’s going to be variant after variant after variant,” she said. “This is never going to stop, and still the things that we knew last year that protected us still are the same things that are protecting us now.”

Those things, besides getting vaccinated, include wearing a mask and avoiding crowds and cramped spaces, she said. The virus, delta variant or otherwise, is here to stay.

“It’s going to be here for the rest of our lives,” Cervantes said. “My life, my daughter’s life, her kid’s life, everybody’s.”

Eventually, the virus may become like other mild, seasonal coronaviruses “that we don’t even think about,” she said. That’s because a truly successful respiratory virus — meaning a virus that keeps multiplying and spreading — needs people to come into contact with each other. 

If a virus makes the majority of people infected severely ill, it limits their contact with other people and thus its own ability to spread. A virus that only results in a mild cold, however, won’t keep people from each other and therefore spreads more.

“But it’s going to take some time to get there,” she said. “And until then, we need to protect ourselves and those around us from getting sick and dying.”

Alexis Allison is the health reporter at the Fort Worth Report. Her position is supported by a grant from Texas Health Resources. Contact her by email or via Twitter. At the Fort Worth Report, news decisions are made independently of our board members and financial supporters. Read more about our editorial independence policy here.

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Alexis Allison covers health for the Fort Worth Report. When she can, she'll slip in an illustration or two. Allison is a former high school English teacher and hopes her journalism is likewise educational....

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