Research Summaries

In this RECOVER study, researchers looked at how Long COVID might affect pregnancy and birth. Between October 2021 and January 2024, researchers followed 603 pregnant women who had COVID-19 before or during pregnancy. This group included 118 women who were considered likely to have Long COVID based on the symptoms they experienced before or during their pregnancy. Researchers found that likely having Long COVID was not linked to a higher risk of babies being born too early (known as premature birth) or other major complications, like needing a cesarean section (or C-section, which is a way to deliver a baby through surgery), being admitted to a neonatal intensive care unit (NICU), or being smaller than expected at birth. One analysis showed that women who likely had Long COVID had a higher risk of high blood pressure disorders during pregnancy. Overall, researchers did not find a higher risk of many pregnancy complications among women who likely had Long COVID. However, more research is needed to fully understand how Long COVID may affect pregnancy and help guide patient care.

We need good ways to measure how adults with Long COVID are feeling and functioning so that we can test new therapies that may be able to help them feel better. Since very few surveys have been specifically designed for Long COVID, we wanted to see how well 4 existing surveys worked by asking adults with Long COVID to give us feedback. 30 English-speaking adults with Long COVID reviewed the surveys during an interview. Evidence from the interviews indicated that adults with Long COVID could understand the questions within the surveys and most of the items were relevant to their experience with Long COVID. Our findings support use of the 4 surveys in the Long COVID clinical trial they were chosen for, and we also identified future ways to make these surveys even better for this population.

Researchers wanted to know why some children get sicker than others when they get COVID-19. Different versions (variants) of SARS-CoV-2, the virus that causes COVID-19, can affect children differently. A child’s age, sex, race, or ethnicity (demographic factors) may also play a role in determining which COVID symptoms they experience—and how burdensome (severe) those symptoms become.

Researchers reviewed electronic health record (EHR) data from a large group of children (ages 0–25) who visited Children’s Hospital Los Angeles between 2020 and 2024 and tested positive for SARS-CoV-2. Next, researchers analyzed biosamples to identify which viral variant was responsible for causing a child's COVID-19. Researchers then compared COVID-19 severity between different viral variants and demographic factors.

Researchers found that COVID-19 caused by the Omicron variant was more likely to be associated with moderate or severe COVID-19 in children compared to COVID-19 caused by earlier variants, like Delta or Epsilon. This finding contrasts with studies in adults that generally found that Omicron infections were milder. The authors also noted that Long COVID cases did not appear to cluster around specific variant periods, suggesting that children’s risk of developing Long COVID may not be tied to a particular variant in the same way it may be in adults.

In terms of demographic factors, researchers found that children who were male had an increased likelihood of experiencing moderate or severe COVID-19 compared with females. Younger children (0–5 years) showed an increased likelihood of experiencing moderate or severe COVID-19 compared to older children. Researchers also found that COVID-19 severity can differ across racial and ethnic groups. For example, Hispanic/Latino and White children included in the study were less likely to develop severe COVID-19 as their age increased, while the data showed Asian children showed a slight increase in severe illness at older ages.

These findings suggest that age, race and ethnicity, and viral variants may interact in complex ways to influence how sick a child becomes with COVID-19. Understanding how viral variants interact with children’s demographic characteristics could inform how health providers care for children who may be at higher risk of experiencing severe COVID-19 or Long COVID.

In this RECOVER study, researchers wanted to learn how Long COVID affects the everyday functioning of children, teenagers, and young adults. Researchers examined the electronic health records (EHRs) of 686 children and young adults under 21 years old, including 651 who got COVID-19 and received care in 21 hospitals across the U.S. They compared young people who had Long COVID to those who had COVID-19 but did not have Long COVID. They found that young people with Long COVID were more likely to have trouble in school, need extra school support, and develop new or worsening behavioral or mental health issues like anxiety and depression. This study is important because it highlights that doctors should ask about school, daily activities, and emotional well-being when caring for young people who’ve had COVID-19. Long COVID can affect these parts of everyday life and require extra support.

RECOVER researchers looked at whether taking selective serotonin reuptake inhibitors (SSRIs) and serotonin–norepinephrine reuptake inhibitors (SNRIs) around the time of having COVID-19 was linked to Long COVID in children, teenagers, and young adults. SSRIs and SNRIs are medicines used to manage mood and mental health symptoms. Researchers reviewed the electronic health records (EHRs) of more than 110,000 young people (ages 5 to 20) who had neuropsychiatric conditions and COVID-19. Neuropsychiatric conditions are disorders that affect how the brain works and how a person thinks, feels, or acts. Researchers compared young people who took SSRIs or SNRIs to those who did not. The study found that taking SSRIs or SNRIs was not linked to a higher or lower chance of receiving a Long COVID diagnosis. However, young people taking these medicines were less likely to experience fever, chills, or hair loss after having COVID-19. Young people taking these medicines were more likely to experience extreme tiredness (fatigue), memory problems, and postural orthostatic tachycardia syndrome (POTS, which is a condition that can cause a fast heart rate when standing up). These findings are important because they suggest that children, teens, and young adults taking SSRIs or SNRIs may have different long-term symptoms after getting COVID-19, which doctors should monitor.

In this RECOVER study, researchers looked at the heart and lung health of 1,475 adults about 21 months after getting COVID-19. The study used a wearable wrist device (called a Fitbit) to take measurements of heart and lung health. Researchers found that adults with more Long COVID symptoms showed signs of lower physical fitness. These adults had higher resting heart rate, lower heart rate variability (a measure of heart stress), took fewer daily steps, and spent less time being active. People with lower physical fitness and activity levels also reported having more symptoms, like feeling very tired (fatigue), dizziness, and feeling worse after activity. These findings show that Long COVID may be linked to lasting problems with physical fitness and daily activity almost 2 years after getting COVID-19. This study is important because it points out how wearable wrist devices may help researchers and doctors track how Long COVID affects the body over time.

In this RECOVER study, researchers looked at whether children who received steroids soon after getting COVID-19 were less likely to develop Long COVID. Steroids are medicines that help with inflammation (swelling and irritation) in the body. Researchers reviewed the electronic health records (EHRs) of more than 850,000 children under 19 years old who had a positive COVID-19 test, a COVID-19 diagnosis, or received antiviral medicines for COVID-19 between March 2020 and April 2024. Researchers then compared children who received steroids within 12 days of getting COVID-19 to those who did not. They also looked at children who were hospitalized and children who were treated at home. Researchers found that steroid use was not linked to a lower risk of developing Long COVID. However, children who were not hospitalized with COVID-19 and took steroids had a lower risk of experiencing stomach problems associated with Long COVID. This study is important because it shows that early steroid use was not linked to a lower risk of Long COVID in children. More research is needed to understand which treatments may help prevent long-term symptoms from developing in children who get COVID-19.

In this RECOVER study, researchers looked at how well COVID-19 vaccines protected children and adolescents who’d already had COVID-19 from getting it again. Researchers reviewed the electronic health records (EHRs) of nearly 600,000 children ages 5–11 and adolescents ages 12–17. These young people received health care at 37 children’s hospitals located across the US. Researchers compared young people who received at least one COVID-19 vaccine with those who had not. Researchers found that vaccine protection changed as new versions (variants) of SARS-CoV-2, the virus that causes COVID-19, appeared. Early in the Omicron variant period, vaccines lowered the chance of getting COVID-19 again by about 62% in children and 65% in adolescents. In the mid-Omicron variant period, the vaccines lowered the chance of getting COVID-19 again by 57% in children but did not work as well for adolescents. During the later Omicron variant period, the vaccines did not stop children or adolescents from getting COVID-19 again. These findings are important because they show that vaccines offered protection against getting COVID-19 again at first, but that protection became weaker as SARS-CoV-2 changed over time.