KANSAS CITY, Kan. — The change in weather means more people are getting sick. That's common this time of year with the flu, COVID-19, and RSV going around. However, doctors at a Kansas City hospital say one illness is more prevalent than others right now. It's called mycoplasma pneumonia, better known as walking pneumonia. Walking pneumonia is a milder form of pneumonia, meaning you can go about your daily routine and not realize you have it. Unlike other illnesses, symptoms start out mild in the first week before getting progressively worse; they include a cough, sore throat, headache, and/or fever. In October, the CDC wrote that since late spring, the number of infections caused by walking pneumonia has been increasing, especially among young children. In fact, the CDC is seeing more cases nationally than it has since the pandemic began in early 2020. Billie Eilish sends love to family of Kearney teens killed in multi-state police chase We asked Dr. Shawn Sood, a pediatric intensivist at KU Health why that is. “Every three to four years immunity to mycoplasma waxes and wanes. Now the immunity has waned and we’re seeing more kids clustered together, so we’re seeing a higher rate of walking pneumonia in children especially," he said. While anyone can get walking pneumonia, young kids are most at-risk. "Last year I feel like RSV was higher, two years prior COVID, and now we're facing more mycoplasma cases," Sood said. He explained that since symptoms start with a minor cough or sore throat, infected kids go to school and spread it, not realizing they're sick. Since walking pneumonia is a bacterial infection and not a virus, there's no vaccine. "If your child's having this lingering cough, sore throat, or fever have them checked out," Sood added. FOX4 also spoke with James Balmer, a music teacher who's recovering from a 10 to 12-day illness. "I still have a residual cough from it," he said. He went to his doctor in early November after getting sick at a choir event with his students. While they didn't officially diagnosis him with anything, he could feel whatever it was starting to go into his lungs. “We managed to catch it before it did get into the chest, and they would’ve needed heavier antibiotics to get it out of me. So, I was lucky this time," he said. Balmer teaches music to all grade levels, and like Sood, he said he's noticed the age group most impacted is elementary-aged students. "There's a lot of it there just because of the age grouping, and you'll see one or two [students] out for two or three days," he said. When asked if he wished parents would keep sick kids at home, he quickly replied yes. Walking pneumonia needs to be caught within 72 hours for antibiotics to be effective. If left untreated for more than a week, it can lead to permanent lung damage, or in rare cases, neurological issues like seizures or a wobbly walk. "We've also seen kids who had untreated walking pneumonia with severe respiratory symptoms. A lot of these kids have asthma or are born prematurely, and some of these kids are requiring the ventilator," added Sood. Download the FOX4 News app on iPhone and Android While the situation changes on a weekly basis, he said three children are currently in the ICU at KU Health with respiratory illnesses. He expects cases to only increase as kids spend more time indoors during the winter months, especially with holiday break coming up and families traveling. If you think your child is sick, take them to their pediatrician immediately.