Researchers at Vanderbilt University Medical Center (VUMC) are leading a nationwide study to determine the rate of novel coronavirus infection in U.S. children and their families.
The study, named the HEROS (Human Epidemiology and Response to SARS-CoV-2) study and funded by the National Institute of Allergy and Infectious Diseases (NIAID), aims to gain insight into how many children ages 1 to 21 have been infected, the percentage of those infected who develop symptoms of COVID-19 and any differences in immune responses to the virus between children and adults within the same household.
It will also examine whether infection rates differ between children who have asthma or other allergies and children who do not, including the impact of topical steroids used to treat asthma and allergies.
Across the globe, children have much less commonly developed severe COVID-19 compared to adults. But, according to Tina Hartert, MD, MPH, professor of Medicine in VUMC's Division of Allergy, Pulmonary and Critical Care Medicine and the lead investigator for the study, a lack of symptoms doesn't necessarily offer knowledge into infection rates.
"It's not known whether children are more resistant to the virus or whether they are infected by the virus just as frequently as adults but don't get symptoms. One consistent trend recognized early in the pandemic was that children weren't as often becoming critically ill compared with adults, but this doesn't equate to children not getting infected," said Hartert, also VUMC's Vice President for Translational Research, director of the Center for Asthma Research and the Lulu H. Owen Professor of Medicine.
"Settling this debate will require large, high-quality population studies that include longitudinal sampling and test for the presence of antibodies in the blood as a marker of previous infection."
The study will be conducted entirely remotely and will rapidly enroll 6,000 people from at least 2,000 families in 10 U.S. cities who are already participating in pediatric research studies funded by the National Institutes of Health.
Both healthy children and children with asthma will be included, and families will be followed for six months to determine who gets infected with the virus and whether the virus is then transmitted between family members.
Participating families will collect and mail in nasal swabs from each family member every two weeks for laboratory analysis, collect baseline stool swabs and complete online questionnaires about symptoms, social distancing practices, potential exposure to those who are sick and activities conducted outside the home.
In addition to biweekly sampling, if someone in the family shows symptoms of a viral illness, another questionnaire will help the family determine the likelihood that the illness is COVID-19. If COVID-19 is likely, families will collect additional nasal swabs from all members of the household and a stool sample from the symptomatic participant for lab analysis within 24 hours.
Families will also submit blood samples for antibody testing using a capillary blood self-collection device at two weeks, 18 weeks and 24 weeks following enrollment as well as three weeks after their first case of COVID-19, if applicable.
Aside from offering insight into transmission and infection rates among children with and without asthma, Hartert says the study will offer broader knowledge into the incidence of novel coronavirus infection across the U.S. population, spanning both children and adults. It will also provide answers regarding differences in immune response and novel coronavirus receptors on cells from the noses of children, adults and those with allergic asthma.
"So far, data on the extent of novel coronavirus infection in the U.S. population have been mostly limited to people who physically interact with the health care system: those who are tested -- especially those who test positive -- and those with severe disease. These data have provided us real-time guidance in a setting of limited test availability, but they don't enable us to understand the full extent of infection in the entire population," said Hartert.
"This study will help fill this knowledge gap, aid in understanding why children less commonly develop severe infection and meaningfully inform public health interventions."
This research is supported by grant AI095227.