ROCHESTER, N.Y. (WROC) — Thirteen-year-old Martha Kelley was babysitting late last month for some of her father’s colleagues. “They have twin boys,” she says. “They’re so cute!”

She says that one of the kids coughed on her. Martha is fully vaccinated against COVID and was not wearing a mask. “At the time I’m like, ‘That’s pretty gross, but too late to do anything now.'”

The next week, Martha started feeling sick, she thought it was a tough cold, but didn’t rule out COVID-19. “I had a sore throat. I was coughing. I was really congested.”

A trip to the doctor’s office revealed the diagnosis was Respiratory Syncytial Virus, a virus that usually hits in the winter, but is spreading now, in the offseason. RSV can feel like you’ve got a case of COVID, and medical professionals are asking anyone with some of these symptoms to see a doctor, even if vaccinated.

Dr. Elizabeth Murray, based in Central New York, says RSV has been around a long time. “This is a germ that causes cold-like symptoms, but really profound mucus,” says Murray. She says that RSV usually impacts babies and seniors the most.

The fact that it’s circulating during the summer is unusual, she adds. “This is what fills our hospitals full of patients during the flu season,” Murray says.

Murray says there’s a huge overlap with COVID symptoms. “Right now the recommendations—as both are in the community—would be to get tested for COVID if you start to have symptoms.” She also says getting tested now is crucial to detect any COVID variants in the community.

RSV is a virus, so antibiotics don’t work. She says time and rest are best, advice that Martha has followed. She’s still on the mend. “I feel good, I have energy and I can do stuff. I’m a little sniffly,” she says, smiling.

Currently, the CDC says RSV is circulating in the highest numbers right now in the American South.