Long-term symptoms for children who have been infected with COVID-19 are very uncommon but do happen, according to experts and a few recent studies.
Although most people with COVID-19 get better within a few weeks of illness, some experience post-COVID-19 conditions, such as headaches, dizziness and difficulty breathing more than four weeks after being infected. This is called “long COVID” according to the U.S. Centres for Disease Control (CDC).
“Children have a really robust immune system response to infection with COVID,” Fatima Kakkar, a pediatric infectious diseases specialist at CHU Sainte-Justine in Montreal said. “We have a study where we’re doing antibody levels and we’re comparing kids versus parents among families that have had COVID, and we’re seeing much higher levels of antibodies in kids versus adults.”
Hospitals across Canada have set up long-term COVID-19 clinics to help treat people – mainly adults – with the symptoms, such as fatigue, shortness of breath and a persistent cough. But pediatric clinics are not seeing an overwhelming amount of children with these long-lasting symptoms, Kakkar said.
And for the children who do show the long-haul symptoms, Kakkar said, doctors across Canada haven’t been able to “pinpoint a biological abnormality” in blood tests or imaging that cause it.
It’s not just Canadian doctors who are seeing a low number of kids with lasting COVID-19 symptoms. Three recent studies show that kids who test positive for COVID-19 have a low chance of bearing long-haul symptoms and needing hospitalization.
A large study published on May 8 out of King’s College in the United Kingdom looked at data from 258,790 children aged 5-17 years old, of which 1,734 tested positive for COVID-19 during the period of March 2020 to February 2021.
Out of the children who contracted the virus, the most common symptoms were headaches (62.2 per cent) and fatigue (55 per cent).
The children who tested positive for COVID-19 usually fell ill for six days, compared to 11 days in adults, the study found.
A little more than four per cent of children were sick 28 days after testing positive, and the most common symptoms were fatigue, headache and loss of smell. Only 1.8 per cent of children experienced symptoms 56 days after testing positive for the virus.
Older children were also more likely to exhibit long-term symptoms than younger ones, the study added.
The study concluded that long-term illness “does occur” but is “uncommon” for children after being infected with the virus. Only a small portion of kids have illness symptoms beyond four weeks and most children “resolve all symptoms” by eight weeks. There was also no need for hospitalization in most cases, the study showed.
The data also showed that 13.3 per cent of adults infected with the virus had symptoms for four weeks.
Another, much smaller study out of Australia posted in the Lancet last month found a very low occurrence of COVID-19 long-haul symptoms in children.
Follow-up data from a group of 171 children in Melbourne, three to six months after contracting COVID-19, found that eight per cent of children had post-acute COVID-19 symptoms. The most common symptoms were a mild cough (four per cent) and fatigue (two per cent).
The duration of post-viral cough ranged from three to eight weeks and post-viral fatigue ranged from six to eight weeks, the study found.
“These findings contrast those of studies of COVID-19 in adults, which have identified multisystem complications and a higher prevalence and severity of persistent symptoms,” the study concluded.
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The latest study on children and long-haul COVID-19 symptoms was published May 21 by the University of Zurich. It found a low prevalence of symptoms compatible with long haul COVID-19 in children six months after testing positive.
Kakkar believes one of the reasons children exhibit fewer symptoms may be because of their strong immune system. This may be one of the reasons why COVID-19 vaccines are reportedly more effective in young people than adults.
“And I think the strong antibody response might be part of what’s playing into the fact that they’re not getting as severe COVID and potentially not as severe as long-term COVID,” Kakkar added.
Rare, but can still happen
Anna Banerji, a pediatric infectious disease specialist at the University of Toronto, said she is not surprised that children can still develop chronic COVID-19 symptoms.
She is currently treating a young patient who was diagnosed with coronavirus more than a year ago and is still experiencing symptoms.
The patient “is still suffering from shortness of breath and an inability to focus,” Banerji explained. “And this is someone who was very active, did well in school, and had no other prior health problems and now has COVID long-hauler syndrome.”
She believes the effects of COVID-19 on children long-term are still “relatively new” in the scientific community.
“I think there’s a lot of assumptions that kids really are not impacted by COVID,” she said.
According to the CDC, children with severe COVID-19 may develop respiratory failure, heart inflammation and multi-organ system failure. Some children with COVID-19 have developed other serious problems like intussusception (a condition where part of the intestine folds onto itself) or multisystem inflammatory syndrome (MIS-C), which includes a high fever, a skin rash and stomach pain.
A small study out of Italy found that long-term effects of COVID-19 may be a problem for children, too.
The study was posted Jan. 26 on medRxiv ahead of peer review.
Doctors at a large Italian hospital tracked 129 children and teens with COVID-19 who were otherwise generally healthy. At an average of about five months after their diagnosis, only about 42 per cent had completely recovered.
Roughly one in three children still had one or two symptoms, while more than one in five children had three or more symptoms.
The most common persistent problems were insomnia (reported by 18.6 per cent), respiratory symptoms including pain and chest tightness (14.7 per cent), nasal congestion (12.4 per cent), fatigue (10.8 per cent), muscle pain (10.1 per cent) and concentration difficulties (10.1 per cent).
There are also clinics in the U.S. that have popped up over the past year in order to address the long-haul coronavirus symptoms in children — a sign that the issue may be more complex than first believed.
For example, earlier this year, the Norton Children’s Hospital in Louisville, Ky., opened a “COVID-19 follow-up clinic” for children and teenagers experiencing persistent effects of COVID-19. It’s designed to help children manage long-term effects like fatigue and body aches that last longer than two weeks.
The Michigan Medicine C.S. Mott Children’s Hospital also recently launched a new clinic that focuses on children and teens who experience lingering symptoms after COVID, including respiratory issues, fatigue and joint pain, according to the hospital’s website.
While the issue of COVID-19 long-hauler syndrome in children is still relatively new, both Banerji and Kakkar argue that kids should get vaccinated as soon as possible for the virus.
Currently, children aged 12 and up can get vaccinated in Canada.
“We want kids to be vaccinated because even if it’s rare, we really don’t want them to get these symptoms like post-COVID inflammatory syndrome (MIS), which can be very severe,” Kakkar said
She added that it’s important people go see their family doctor if they are worried they or their children have symptoms of long-COVID.
— With files from Reuters