(NBC) - While swine flu has been off the radar for many Americans, doctors have continued to see a steady number of H1N1 patients.
A recent spike in severe cases in the Southeast combined with new statistics that show just 1-in-4 Americans have been vaccinated has many experts warning the virus is not gone.
For many doctors the sights and sounds of spring mean the waiting room is filling up with allergy patients, but there's another reason people are heading to the doctor.
Dr. Steven Gilchrist is a family physician in Charlotte, NC. It's one of the most allergenic cities in the US. This year it's also part of a spring spoke in H1N1 cases.
"Totally takes you off guard to see flu in 70 degree weather," Gilchrist said. "We have seen a few cases recently within the last couple of weeks."
CDC officials, like Dr. William Shaffner, confirm the virus is still circulating, particularly in the Southeast.
"The H1N1 virus hasn't disappeared, it's still smoldering, still being transmitted in our communities," Shaffner said.
Experts don't know if it is an outbreak or a blip on the map. What they do know is that doctors have given more than 80 million doses of vaccine. That still leaves millions more Americans vulnerable and some of the vaccine is getting closer to its expiration date.
"There have been several different vaccine formulations," Shaffner explained. "Some of them have expiration date that goes into fall, so there's still good vaccine out there."
Hundreds of thousands of does are available so if you can't handle the spring sneeze, consider asking your doctor for a swine flu shot during your allergy checkup.
Nearly all of the patients hospitalized now did not get the shot and experts can't predict how long the virus will be circulating. Last year cases popped up throughout the summer.