TRAVIS COUNTY (KXAN) — Austin has now moved into Stage 4 of the COVID-19 risk-based guidelines as cases continue to rise mainly among the unvaccinated population.

As the delta variant continues to spread at an alarming rate, medical experts are urging people to get the vaccine.

“The COVID virus seems to be throwing us a new curveball almost weekly,” said Dr. William Schaffner, an infectious disease expert with Vanderbilt University Medical Center in Nashville, Tennessee.

Hospitals around the nation are once again seeing more people show up with COVID-19 complications.

“It is really spreading now and really causing cases to increase,” Schaffner said. “Principally and overwhelmingly among unvaccinated people.”

Can you still get COVID-19 if you have had the vaccine?

“The vaccines were designed to prevent serious disease and keep us out of the hospital,” said Schaffner. “We recognize that can still happen, so you can get infected, but you are very unlikely to become seriously ill.”

People with compromised immune systems could be more at risk of having complications even with the vaccine.

“This is anywhere from 2% to 4% of the population,” Schaffner said. “These are people who can’t respond optimally to the vaccine so they may not get that same amount of protection.”

What about returning to work, school, or even going out into a crowd? Should those who are vaccinated wear a mask?

“Let’s say we have older people with diabetes or heart disease or lung disease or are immune compromised,” Schaffner said. “They, even though they are vaccinated, if they go out in a crowd indoors they might want to wear a mask.”

Schaffner says people can still die from the virus even with the vaccine.

“We can’t expect perfection, but we can anticipate excellence,” Schaffner said.