“Long COVID” can hamper a person’s recovery from the coronavirus for months. Along with suffering from dozens of potential symptoms, the exact length of long COVID remains a mystery. However, a new study finds children who contract COVID-19 rarely see these after-effects continue for more than 12 weeks.

A team from the Murdoch Children’s Research Institute (MCRI) say the most common symptoms are headache, fatigue, sleep disturbance, concentration difficulties, and abdominal pain. While children may still have to deal with side-effects from a COVID infection, pediatricians say it’s “reassuring” the issues may be less of a concern than in adults.

“The low risk posed by acute disease means that one of the key benefits of COVID vaccination of children and adolescents might be to protect them from long COVID,” says lead author Professor Nigel Curtis from the University of Melbourne in a media release. “An accurate determination of the risk of long COVID in this age group is therefore crucial in the debate about the risks and benefits of vaccination.”

Is the Delta variant really making things worse?

The Australian team pooled data from 14 studies around the world involving 19,426 youngsters with persistent problems after infection. Analysis also found those with obesity, chronic kidney disease, cardiovascular disease, and immune system disorders are 25 times more likely to suffer a severe case of COVID.

Children with COVID-19 usually have mild symptoms, or none at all, and low hospitalization rates. Despite this, the risk and features of long COVID remain poorly understood.

“Current studies lack a clear case definition and age-related data, have variable follow-up times, and rely on self- or parent-reported symptoms without a lab confirmation,” Prof. Curtis explains. “Another significant problem is that many studies have low response rates meaning they might overestimate the risk of long COVID.”

The researchers also found that, after 10 months in circulation, infections from the Delta strain have not been more serious in children than previous variants. Children over 12 years-old are eligible to receive the coronavirus vaccine, according to the CDC. Evidence suggests the vaccine more than halves the risk of catching the Delta variant. It also reduces the chances getting very sick or spreading it to someone else.

Long COVID may not be the only thing impacting kids

Prof. Curtis and colleagues say existing studies on long COVID in children and adolescents have major limitations. Some do not show a difference in symptoms between those who have been infected and those who haven’t.

Co-author Dr. Petra Zimmermann of MCRI adds some symptoms of long COVID were difficult to distinguish from the indirect effects of school closures and not seeing friends or participating in sports and hobbies.

“This highlights why it’s critical that future studies involve more rigorous control groups, including children with other infections and those admitted to hospital or intensive care for other reasons,” Dr. Zimmermann says.

Prof. Andrew Steer, co-chair of the MCRI COVID-19 governance group, also points out that the Delta variant is more transmissible. It makes controlling community outbreaks challenging without mitigation risk strategies in place.

“More data is needed to describe the burden of COVID-19 in children and adolescents following the emergence of the highly transmissible Delta variant and because adults have been prioritized for vaccines,” Prof. Steer says. “As restrictions ease and other respiratory viruses increase in circulation, we also need to understand whether co-infection with other respiratory viruses, such as RSV or influenza, increases disease severity in young people.”

According to the American Academy of Pediatrics, over five million children have tested positive for COVID-19 as of Sept. 9. That’s about 15 percent of all coronavirus cases in the United States. Luckily, children only make up one to four percent of COVID hospitalizations and less than one percent of of COVID deaths. As for long COVID however, a previous study finds patients can experience over 200 different symptoms following their infection.