Asymptomatic Spreaders: Young People with COVID-19

In the early stages of the COVID-19 pandemic, it was largely reported that children and young people were not as high risk for contracting or spreading the COVID-19 virus. But now that testing is more widely available, the numbers reveal a very different truth.

“Early in the pandemic, we were seeing very few cases of kids with COVID-19,” says Lael Yonker, MD, a pediatric pulmonologist, researcher and director of the Pediatric Cystic Fibrosis Center at Mass General for Children. “Now, kids under 19 years of age are neck-and-neck with the young adults for the most infected age group.”

According to Alessio Fasano, MD, chief of Pediatric Gastroenterology and Nutrition at Mass General for Children, children can be mildly sick or asymptomatic spreaders as they often have no awareness that they are sick. In addition, they went largely undiagnosed during the early stages of the pandemic due to the lack of tests.

As Drs. Yonker and Fasano were already involved with pediatric research before the pandemic, they had systems and resources in place that have helped to provide a foundation for COVID-19 research. They were among the many researchers interested in studying MIS-C (multi system inflammatory syndrome in children) and children who were known to be infected with the virus but did not exhibit symptoms.

Young People and the First Wave of COVID-19

During the first wave, testing supplies were limited and reserved for people who were at higher risk for developing severe disease. Therefore, the data on COVID rates among children was minimal.

For a while, it almost seemed as though children were spared from the pandemic, as they often exhibited only mild symptoms or were completely asymptomatic. In reality, the data shows that young people of all ages—ranging from babies to college students—can carry just as much viral load as adults. Even if they do not get sick, they are able to spread the virus to others.

As the pandemic continued, health care experts also found out that some children developed MIS-C, a rare complication, about a month after being exposed to the virus—even if they did not exhibit any symptoms.

“We are still trying to understand what causes MIS-C, but there seems to be an immune response that becomes out of control in some ways,” Dr. Yonker says. “It causes high fevers as the first sign, then affects multiple organs and can results in cardiac issues.”

Data on COVID-19 and Young People

Dr. Yonker recently led the most comprehensive study of COVID-19 pediatric patients to date. Despite limited testing availability for young people, the study analyzed data from kids who presented to the hospital or Respiratory Illness Clinic because they:

• Had mild cold symptoms, concerning for COVID
• Had mild/asymptomatic COVID but needed a place to sleep due to hospitalized parents
• Were being treated at the hospital for other injuries or illnesses

“We concluded that kids infected with COVID-19 have very mild symptoms. In fact, COVID symptoms tend to be no different than any common cold,” says Dr. Yonker. “Symptoms alone could not distinguish if kids had COVID or had some other mild respiratory illness. But when we looked at the amount of virus that they were carrying, we saw that it was actually quite high.”

As the researchers have continued their research, they are finding that COVID-19 numbers are on the rise for young people, particularly now that testing is more widespread.

How to Keep Children Safe

Dr. Fasano, who worked in vaccine development for 20 years, cautions that while a vaccine is essential, it will not be a quick fix as it only protects the person who is vaccinated. To protect the community, he says, requires 95% to 97% of the population being vaccinated. In addition, the current vaccines are only being developed and tested for adults. A pediatric vaccine will require additional testing, especially considering the risk of MIS-C.

“We are trying to learn more about MIS-C because it will be really important if you are vaccinating and triggering antibody response, and we want to make sure that we avoid this sort of complication,” he says.

Standard precautions will help slow the spread of the virus until there is a widely available vaccine.

Kids who can safely do so should practice standard COVID-19 safety precautions when they are in the community, including during school and extracurricular activities. This includes:

• Physical distancing
• Wearing masks
• Washing hands

“Regardless of whether children get sick or not, it is the grandparents and the older member of the community who are going to be most at risk of severe disease and hospitalization,” Dr. Yonker says. “Some kids do develop rare complications later on; however, most will be fine. Still, we have to be hyper-vigilant in order to protect those who are most at risk.”