Yeah, it's just hitting the news cycle in several places:
An 8-year-old boy with coronavirus antibodies went into cardiac arrest. His brother's CPR saved his life
is another one - perhaps available in EU? Don't know. But the upshot is that a 15 year old who had learned CPR as a Boy Scout happened to be there when his little brother went into cardiac arrest due to that new CoVid syndrome in children. Little brother never tested positive for the virus and had no symptoms, but upon hospitalization, tested positive for the antibodies. That's why Dr Fauci is asking people to hold off on thinking we know a lot about CoVid.
The older brother kept the little brother alive until the paramedics got there and used the defrib on him.
The little boy did have a fever in April but his pediatrician said it was just the flu. This article from California may meet EU standards:
New York teenager performs CPR, saves 8-year-old brother with coronavirus-related condition who went into cardiac arrest
It also has new information. No one in the family thinks they had CV but so far no news on whether the parents have been tested.