A new study is challenging the idea that younger children are somehow less susceptible to SARS-CoV-2 infection. Children under the age of five have been found to carry just as much or carry more coronavirus in their noses and throats than older kids or adults. Severe cases of COVID-19 in children are rare, but do exist, and have been linked to serious and long-term side effects.

After breaking their participants down into three age categories younger children, older children, and adults researchers found that the youngest group harbored between 10 times and 100 times more, carry more coronavirus than the other two. While the results cannot speak to children’s ability to transmit the disease to others, they come at a time when schools nationwide weighing the risks of opening again in the fall.

A baby with COVID-19:

A very sick newborn, treated at Children’s National Hospital in Washington, D.C., was found to have not only a new variant of the novel coronavirus, but a viral load 51,418 times higher than other young patients, according to the Washington Post. It’s not clear how common or how risky this new variant might be. The database found eight other cases of this variant in the US mid-Atlantic region, according to a pre-print study, which has not yet been peer-reviewed, on variations in children. The variant, researchers said, has a different type of spike protein structure that may make it more infectious. It’s not clear whether this new variant explains the huge number of viral particles detected in the infant’s nose.

Scientists have also been turning to other diseases to assess how likely children are to transmit the coronavirus, but evidence is still lacking. Young children may be less likely to infect other people when they get sick, although the CDC still suggests that everyone could potentially spread the disease. But researchers still don’t fully understand all the implications of coronavirus for children and babies.