(CNN)Ava is what Heather Brugger calls her "miracle child." Of her four children, the 20-year-old is the one who is "firing on all cylinders all the time," the kind of kid who knows all the passwords to make everyone's electronics in the house work. Covid-19, though, is testing Ava's mettle and it's been almost a year since her initial diagnosis.
"I was super sick," Ava said. "I had it bad."
Ava Brugger, a champion equestrian, got sick with Covid-19 last August and has long Covid now. She said it feels a little like she has a concussion, and she's frustrated. "I just want to feel normal and happy and energetic again."
She couldn't breathe. She had stomach problems and other infections, including mononucleosis, that eventually sent her to the ER.
In all, it took six weeks before the award-winning equestrian at the College of Charleston was cleared to ride again, but she hasn't ridden competitively yet.
"She tells me it feels like she has a concussion," her mother said. "It's like brain fog and fatigue and almost constant headaches."
When she didn't get better, they took Ava to Children's National Hospital in Washington, D.C. to its interdisciplinary clinic for children and adolescents with long Covid-19.
The Bruggers are optimistic, but doctors still don't know a lot about long Covid-19 in young people. It's such a new condition it doesn't even have one name, and is also called post-Covid or long haul.
There's interim guidance from the US Centers for Disease Control and Prevention. It's believed to disproportionately impact Black and Hispanic children. Symptoms can include difficulty in breathing, tiredness, headache, joint pain, sleep problems, mood changes and more, four or more weeks after an initial infection, but most long Covid research has been in adults.
"If you ask me a question about chickenpox, there's a lot of detail about chickenpox. It's been studied for 70 years, but Covid's only been around a year," said Dr. Ben Katz, who has treated kids with long Covid as a pediatric infectious disease specialist at Ann & Robert H. Lurie Children's Hospital of Chicago.
Doctors know how to treat the symptoms, Katz said, but there are still many mysteries.
So, Children's National Hospital in Washington, D.C., in partnership with the National Institute of Allergy and Infectious Diseases, announced Tuesday that they will start a $40 million study on long Covid and multisystem inflammatory syndrome in children, or MIS-C. It will be one of several NIH efforts.
Dr. Bill Kapogiannis, program director in the NIH's Maternal and Pediatric Infectious Disease Branch, said they've been trying to understand MIS-C and also the short, medium, and long term effects of Covid-19 in kids and adults since last spring.
"We don't even have a great definition for it in adults, and about children we don't even know what the definition should be of what we're looking for," Kapogiannis said.
Once scientists agree on a definition, they can look at targets for treatment and prevention.
"You need a very focused, large-scale effort that really has a standardized approach to find the answers," he said.
Up to 2,000 young people will be enrolled in the multi-year study announced Tuesday. At least half will have recovered from asymptomatic or symptomatic Covid-19 or MIS-C, a rare complication that can sometimes follow an infection.
Scientists hope the study will help them better understand the long-term physical and mental health impacts after acute illness. The study will also try and determine how often children experience long-term problems from Covid-19, what the risk factors are, and how the disease could impact a child's quality of life.
Little is known about why some children have long-term effects from the disease and others don't. Many in treatment for long Covid were asymptomatic or had a mild case. At this time, it appears that severe Covid-19 illness is rare among children.
More than 4 million children and teens have tested positive for Covid-19 since the start of the pandemic, according to the American Academy of Pediatrics. It's believed anywhere between 2% and 10% have long Covid, but the potential number of children who have long Covid may be much bigger than the number hospitals are treating.
"I'm guessing it's just the tip of the iceberg," said Dr. Alexandra Yonts, an infectious diseases specialist and director of the long Covid clinic that started up in May at Children's National Hospital.
Since symptoms vary, it may be difficult for parents or pediatricians to notice when a child has this condition.
"It's hard to say you know it definitely is this one thing with these five symptoms, confirmed with this one lab result, because it isn't that," said Yonts.
For now, hospitals across the country are tailoring treatment to each child. The help can't come soon enough.
"A lot of them come in there with just feeling lost and like they don't know what's wrong and they've lost everything that was normal about their lives," Yonts said.
At Yonts' clinic, to better understand what symptoms doctors need to treat, all patients are screened, get lab work, and then get a multidisciplinary team to address their different symptoms. There's physical medicine, psychological help, and rehabilitation.
One symptom they all seem to share, to varying levels, is persistent fatigue. Some have "a little bit of brain fog." For others it's much worse.
"We had a couple of patients who, like literally for the first three months after they had Covid couldn't stay awake for more than half an hour at a time," Yonts said.
Hospitals have experience treating children for post infection syndrome, so there is at least a framework for clinics to follow.
Doctors work with the child to set small goals, much like when they treat kids with a concussion, to ease them back into physical and mental activity. They may start with reading for pleasure, or a five minute walk, and build from there.
"I think that's honestly a huge part of it -- just establishing goals, giving some hope, and having a plan," Yonts said
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Treatment helps, but Ava, who just turned 20 last week, is still struggling.
"It's definitely frustrating, and I just like want to feel normal and happy and energetic again," she said.
But she has a feeling she'll get better with the help of others.
"I've been very lucky that everyone around me has been very supportive and understanding when I haven't been feeling good, that helped a lot," she said.
