The highly contagious Delta variant continues to spread across the U.S. and around the world as it has become the dominant strain of the virus.

The Delta variant has created a surge in cases. The Centers for Disease Control and Prevention on Friday reported there were more than 100,000 daily cases, the highest number since February.

One medical expert told CNN that "even the young and the healthy, including pregnant patients, are now starting to fill up our hospitals."

“This is like a wildfire,” said Dr. Michelle Barron, a senior medical director of infection prevention and control at Colorado’s UCHealth.

By early June, the Delta variant, which was first identified in India, accounted for more than 6% of all infections in the U.S. and rapidly became the dominant strain in the U.K., was responsible for more than 90% of infections and causing COVID surges in parts of England.

On Friday, the New York Times cited an internal document from the CDC that described the Delta variant as "much more contagious, more likely to break through protections afforded by the vaccines and may cause more severe disease than all other known versions of the virus."

According to the CDC, the Delta variant is as contagious as chickenpox and far more contagious than the common cold or flu.

The Associated Press reported that 99% of COVID-related hospitalizations and deaths are from the unvaccinated.

Vaccinated people who contract the virus will only experience mild symptoms, but if a vaccinated person were to pass the virus to an unvaccinated person, the unvaccinated person might suffer severe health consequences.

“We have to be vaccinated and masked, or we will, for the fourth time, endure another surge, and out of that will come worse variants,” said Dr. Gregory Poland, infectious disease expert at the Mayo Clinic.

More unvaccinated Americans may be inclined to get vaccinated because of the spread of the Delta variant, one expert noted.

"People are waking up to this," Dr. Francis Collins, Director of the National Institutes of Health, told CNN Sunday. "That's what desperately needs to happen if we are going to get this Delta variant put back in its place, because right now it is having a pretty big party in the middle of the country."

On Friday, Deputy White House press secretary Karine Jean-Pierre said there were half a million shots that day, the highest daily tally since July 1.

Coronavirus CDC