Children develop many other difficult-to-define syndromes after having covid. Fatigue is common. Some children might have a cough or sore throat for months. Others take months to recover their sense of taste and smell. Some are too weak to attend school or have signs of heart damage, others experience seizures and blackouts. Symptoms can temporarily resolve before relapsing. Some children have a single lasting symptom, while many others experience a constellation.
The symptoms vary in their severity, too—and these differences may be overlooked in studies that compare children who did or did not contract SARS-CoV-2. A questionnaire that asks children if they had a headache might not differentiate mild head pain from a severe experience that leaves a child unable to open their eyes or get out of bed.
In truth, long covid is likely to encompass several different conditions. “It’s not a diagnosis, it’s not a disease … we don’t know what it is,” says Forrest. “It’s squishy.” Stephenson and Mcfarland have met with representatives of the WHO to discuss a potential definition for long covid in children, but none has been established so far. The WHO says it will need more studies and research.
While progress on finding a clinical definition has stalled, there has at least been some agreement over a way to define long covid in children for research purposes.
In February, Stephenson and his colleagues published a definition of long covid in children to be used in research that states that symptoms must follow a confirmed case of covid-19, must impact the child’s life and physical, mental, or social well-being, and must persist for at least 12 weeks. Stephenson hopes the WHO will align its definition with this one, but in the meantime this definition should at least help ensure that researchers are studying the same thing, he says.
The only way to prevent long covid is to avoid contracting SARS-CoV-2, which is why many doctors and scientists encourage people to get vaccinated. It is not clear how much protection vaccines may offer against long covid, but a few recent studies suggest that vaccination can reduce a child’s risk of severe illness from the omicron variant by two-thirds.
Long covid is thought to more frequently follow more severe infections, but it can also follow mild or even asymptomatic cases. “This seems to be more of the case in children, which I think is unique and disturbing,” says Yvonne Maldonado, an infectious disease pediatrician based at Stanford University and chair of the American Academy of Pediatrics’ Committee on Infectious Diseases.
Because vaccinations can reduce the severity of cases, and should reduce transmission, they are recommended for all children over the age of 5 in the US. As of March 30, 58% of 12- to 17-year-olds had received both doses of a covid-19 vaccine, according to CDC data published by the American Academy of Pediatrics. Only 27% of those aged 5 to 11 had.
In the UK, covid-19 vaccinations for young children are the center of another debate. The UK’s Joint Committee on Vaccination and Immunisation (JCVI), which advises the government, announced a plan to offer all children aged 5 to 11 a covid-19 vaccine just last month, and then only on a “non-urgent” basis.
“I think the JCVI have got it right all along,” says Absoud. “The way they’ve left it now is that it’s a choice for families.”
“A hell of a lot of children” are affected
Binita Kane at Manchester University NHS Foundation Trust
Of course, there are other ways to reduce transmission among children. The experts we contacted stressed the importance of keeping schools open, and said that measures such as improving ventilation and air quality, and masking, at least among adult caregivers, during surges of transmission can help keep case numbers down and help prevent both long covid and “long pandemic syndrome.” They are also among the only options we have to protect kids under 5.
All children who are significantly affected by SARS-CoV-2, whether directly or indirectly, will need support to recover, so arguments over the prevalence of long covid in children may be beside the point. “Whether it’s long covid or long pandemic syndrome, everything needs to be treated,” says Villapol.
Even if only 1% of children develop long covid following an infection, the total number of affected children will reach the millions, given how many children have already contracted the virus. The JCVI’s guidance on immunizing children suggests 85% of children in the UK aged 5 to 11 had been infected with the virus by the end of January 2022, before they were eligible for vaccination. “It’s a hell of a lot of children,” says Kane.
Today, Kane’s daughter Jasmin is doing better. A new treatment regime seems to have helped, and while it hasn’t completely restored her energy levels, she is “remarkably improved,” says Kane.
The trouble is, while researchers debate prevalence, the focus is drawn away from biological causes and potential treatments, meaning many other children are still suffering, she says.
“We can’t wait for years,” Kane says. “We need to move on.”