By Stephanie Stahl

PHILADELPHIA (CBS) — The COVID-19 variant from the United Kingdom continues to spread across the Philadelphia region and officials say it’s probably at a higher rate than is being detected. The U.K. variant is set to become the world’s most dominant strain.

While there are just a handful of cases officially confirmed in this area, officials say there could be hundreds.

READ MORE: Thieves Steal ATM From West Philadelphia Laundromat

The University of Pennsylvania is confirming two students have tested positive for the United Kingdom COVID-19 strain. Their cases are linked to travel from the U.K., according to the Daily Pennsylvanian, that says, overall, COVID-19 cases at the university have doubled for the second week in a row with students now back on campus.

“It seems clear that virus is more transmissible,” said Scott Hensley, with Penn’s Institute for Immunology.

Hensley is studying the U.K. variant.

“What we know is that virus has a substitution that allows it to actually attach to our airways more effectively,” Hensley explained. “So you can imagine a virus that actually attaching to our airway cells more effectively, that virus can be transmitted more efficiently and also cause more disease.”

When Can I Get The COVID-19 Vaccine In Pennsylvania, New Jersey Or Delaware?

In Montgomery County, four people with the U.K. variant had no travel history and they appear to have spread the mutation.

READ MORE: A Behind-The-Scenes Look At Longwood Gardens' $250 Million Expansion Project That Gets Underway Today

“We have confirmed additional cases linked to some of these individuals,” Montgomery County Board of Commissioners Chair Dr. Valerie Arkoosh said. “People need to continue to be very careful with mask-wearing, hand-washing and social distancing.”

It’s a trend sweeping the country as the U.K. variant has now been detected in at least 34 states.

“The numbers are doubling every 10 days of that, and by mid-March to late March, it’ll be everywhere,” said Dr. Ashish Jha, dean of the Brown University School of Public Health.

The variant spread is among the reasons many are now wearing two masks. A new report from the Centers for Disease Control and Prevention says double masking can help prevent infection.

“The two-mask situation is really for high-risk things, so when you’re gonna be in a grocery store for any extended period of time, if you’re gonna be indoors with a lot of people,” Jha said.

Doctors say a close fit is most important for masks to be effective.

MORE NEWS: Philadelphia School District, Teacher's Union To Hold News Conference About Return To In-Person Learning, Sources Say

With the U.K. variant, scientists know it’s more contagious and may be associated with an increased risk of death compared to other variants, but more studies are needed to be sure.

Stephanie Stahl