Long COVID Can Affect Children of All Ages, Including Infants

Students in Wendy Verrall second grade class make their hand into a smile to show they are happy, since their mouths are covered, during the first day of class at Tustin Ranch Elementary School in Tustin, CA on Wednesday, August 11, 2021.
Students in Wendy Verrall second grade class make their hand into a smile to show they are happy, since their mouths are covered, during the first day of class at Tustin Ranch Elementary School in Tustin, CA on Wednesday, August 11, 2021.

Paul Bersebach/MediaNews Group/Orange County Register via Getty

A new study shows children from all ages can suffer from long COVID symptoms.

In a study published Wednesday in the journal The Lancet Child & Adolescent Health, parents of over 44,000 children in Denmark, ages zero through 14, responded to a survey to determine the effects of COVID in children.

Approximately 11,000 of the children tested positive between January 2020 and July 2021, and those who did not have the virus were used as a control group.

The study found that children aged 0-3 years old who have had COVID had a higher chance of stomach aches and mood swings after recovering from the virus than the control group of the same age.

RELATED: Pfizer's 3-Dose COVID Vaccine Is 80% Effective in Kids Under 5

Small children with face mask back at school after covid-19
Small children with face mask back at school after covid-19

Getty Images

The common symptoms for children up through age 3 were mood swings, rashes, stomach aches, cough and loss of appetite. Children 4 to 11 years old had mood swings, memory loss and concentration problems. Children between 12 and 14 years old also had memory and concentration issues, mood swings and fatigue.

For each of these symptoms, duration lasted a variety of months, from two months up to 12. And in 12–14 year olds, more girls than boys had at least one symptom lasting more than two months.

The study also found that children 3 and under seemed to have the most problems compared with those children not diagnosed with COVID — 40% experienced symptoms two months after testing positive compared with 27% in the group that did not have COVID.

Never miss a story — sign up for PEOPLE's free daily newsletter to stay up-to-date on the best of what PEOPLE has to offer, from juicy celebrity news to compelling human interest stories.

Finally, Long COVID was present in 427 (31·2%) of 1368 children aged 0–3 years, 1505 (26·5%) of 5684 children aged 4–11 years, and 1077 (32·5%) of 3316 children aged 12–14 years.

Boy getting a flu or coronavirus vaccine in the clinic
Boy getting a flu or coronavirus vaccine in the clinic

Getty Images

The Centers for Disease Control and Prevention first approved the Pfizer-BioNTech vaccine for emergency use in children ages 12 to 15 back in May 2021. The vaccine received the same approval for children ages 5 to 11 six months later in November.

RELATED: FDA Panel Votes to Move Forward with COVID Vaccines for Children as Young as 6 Months Old

Last week, a Food and Drug Administration panel voted unanimously to authorize the use of the Moderna and Pfizer/BioNTech COVID-19 vaccines for children as young as six months old.