So if this information is right, Covid-19 dont seem to cause serious symptoms to kids, but it's a serious threat to older people.
Its just a hypothesis by the way but...
What if it has something to do with information stored in the telomeres?
"Coronavirus: Children as susceptible as adults"
Citing this study:
"The household secondary attack rate was 15%, and children were as likely to be infected as adults."
"We further show that children are at similar risk of infection as the general population, though less likely to have severe symptoms; hence should be considered in analyses of transmission and control."
Keep in mind the above paper hasn't been peer-reviewed yet, understandably so!