Some children are developing 'long Covid', a mysterious condition where a person feels symptoms of the virus long after recovery.
The condition has baffled experts, usually appearing in healthier children who do not suffer from severe cases of the virus.
Symptoms can be wide ranging, from anosmia - lost of taste and smell - to suffering cognitive issues such as 'brain fog', just like they are in adults.
Experts are not quite sure why the condition develops, and how to effectively treat it.
Adam Estrada (pictured) begin to experience severe symptoms of long Covid after a bout with the virus that left his hospitalized. He has experienced hair loss and lost the ability to stand on his own at some points
Estrada was treated by Dr Katharine Clouser in New Jersey at one of the state's only pediatric long Covid treatment clinics. Pictued: Estrada with his mother during a CBS News interview
Dr Katharine Clouser is a hospital pediatrician from Hackensack, New Jersey, and her team at Hackensack Meridian Health are operating one of the few pediatric Covid recovery centers in the state.
Clouser told DailyMail.com she took interest in pediatric long Covid cases after families of patients she had treated at the hospital were following up with her, mentioning their child was still feeling symptoms after recovery.
'As I started to get more and more calls in the late winter [and] early spring ... we thought that it's important that these kids have a place to go as we're learning more about [the condition],' she told DailyMail.com.
One of those children was Aaron Estrada, 4, who contracted the virus a year ago.
He was hospitalized, and after his bout with the virus developed multi-system inflammatory syndrome.
Estrada's condition got so bad that he ended up losing his hair and could not stand on his own for a month.
While Estrada is a more severe case than what many other children experience, solving cases like his has become a challenge for doctors.
She said that she believes somewhere between ten to 15 percent of children who contract the virus will develop long Covid.
Around half of children who contract Covid will be asymptomatic, and when testing supplies were limited early in the pandemic, many children were never even tested for the virus.
Interestingly, children who suffer mild cases of the virus are more likely to develop long Covid than ones with severe cases.
'The kids who have more severe Covid, I'm actually not really seeing so much of my clinic,' Clouser said.
She said many children who did not even know they had Covid will suddenly start reporting symptoms such as joint pain, fatigue, headaches or more.
Then, the child will receive an antibody test and find that they previously had suffered a mild or asymptomatic Covid
