More on kids and COVID-19: HEROS

[DSeid]

There is finally some serious study in progress that may (or may not) confirm the apparent very low infectiousness of children who catch COVID-19 (a key bit of information to get a handle on both for modeling the spread and for deciding about how to handle schools). They have started to enroll families in the Human Epidemiology and Response to SARS-CoV-2 (HEROS) study.

“One interesting feature of this novel coronavirus pandemic is that very few children have become sick with COVID-19 compared to adults,” said NIAID Director Anthony S. Fauci, M.D. “Is this because children are resistant to infection with SARS-CoV-2, or because they are infected but do not develop symptoms? The HEROS study will help us begin to answer these and other key questions.”

The HEROS study team will rapidly enroll 6,000 people from 2,000 U.S. families already participating in NIH-funded pediatric research studies in 11 cities. Study participants will include both healthy children and children with asthma or other allergic conditions. The study team will prospectively follow these children and their families for six months to determine who gets infected with SARS-CoV-2, whether the virus is transmitted to other family members, and which family members with the virus develop COVID-19.

(Bolding mine.)

So far all we know is that there have not been cases of children spreading it to other family members documented in contact tracing, even though we know they catch it. It must still happen but apparently not so much that it has been seen yet. In influenza children are the amplifiers of spread, not so sick but high contact spreaders with everyone even near them, that’s why school closures are a go-to part of the pandemic toolbox; minimally this does not seem to occur to anything like that with COVID-19. To what degree this occurs less than with influenza, less than in asymptomatic adults, is vital to understand to help decide if school shut downs are adding any value and if so how much given its dramatic impacts.
The study will also further investigate the also surprising bit that allergy history may even be protective.

Preliminary evidence suggests that having an allergic condition paradoxically may reduce a person’s susceptibility to SARS-CoV-2 infection and severe COVID-19 disease. A NIAID-funded study(link is external) recently examined upper and lower airway cells for the expression of ACE2, the gene that codes for the receptor that the coronavirus uses to infect cells. ACE2 expression is necessary for a cell to make this receptor, but additional steps also are involved. In both children and adults, respiratory allergy, asthma and controlled allergen exposure were associated with significantly reduced ACE2 expression. The expression of ACE2 was lowest in people with high levels of both asthma and sensitivity to allergens.

The HEROS study will further clarify whether reduced ACE2 gene expression in airway cells of children with allergic diseases correlates with a lower rate of SARS-CoV-2 infection and COVID-19.

This should have been started early on, the answers may be late to inform openings in the Fall, but at least these very important questions are finally being asked.