WILLIAMSON COUNTY, Texas (KXAN) — The Delta COVID-19 variant, a strain of the virus that’s spread more easily, is in Williamson County.

The Williamson County and Cities Health District (WCCHD) confirmed Friday that testing identified three cases of the Delta variant, the first ones officially reported in the Austin area.

“It’s more a matter of when, not if,” said WCCHD Lead Epidemiologist Allison Stewart. “But it was kind of surprising, because they were the first ones that we were aware of that were identified in the TSA O Region, according to the state health department.”

Stewart said chances are, if it’s in her county, it’s in Travis County.

“That’s just the way diseases work. They don’t really just stay put. So yeah, if I was betting, I would bet it would already be there,” she said.

Austin-Travis County Health Authority Dr. Desmar Walkes told KXAN Austin Public Health has not been notified of any Delta variant cases in Travis County.

Delta is a version of the coronavirus that has been found in more than 80 countries since it was first detected in India. It got its name from the World Health Organization, which names notable variants after letters of the Greek alphabet. Officials said it’s about 60% more transmissible than variant B.1.1.7 found in the United Kingdom in late 2020.

WCCHD noted the current scientific evidence states the variant may be associated with an increased risk of hospitalization, but mRNA vaccines like Moderna and Pfizer are still highly effective against it.

Dr. Rodney Young with Texas Tech Physicians told KXAN’s Maggie Glynn because it’s easier to transmit, it could potentially become the dominant strain of the virus in “weeks.”

Stewart said just over half of Williamson County neighbors still aren’t vaccinated.

“If we could get up to… 70% to 80%, we may have a chance to really diminish where the Delta variant could go and could spread,” she said.

For those who are already vaccinated, she tells them not to panic.

“You really don’t have to worry too much about any sort of severe disease outcome if you’ve already been vaccinated,” she said.

Earlier this week, the Texas Department of State Health Services reported only 25 cases of the variant in Texas. It is thought to be responsible for only a small proportion of the current COVID-19 cases in Texas and the United States, but the proportion of cases is growing quickly, and it is estimated to be the dominant strain in the U.S. as early as August.