Here are just a few links that point up very disturbing consequences of using asprin when you have the flu. In 1918, 50-100 million people died from the Spanish flu.
One hypothesis suggests that many flu deaths could actually be attributed to aspirin poisoning. Medical authorities at the time recommended large doses of aspirin of up to 30 grams per day. Today, about four grams would be considered the maximum safe daily dose. Large doses of aspirin can lead to many of the pandemic’s symptoms, including bleeding.
However, death rates seem to have been equally high in some places in the world where aspirin was not so readily available, so the debate continues.
This first article sis why I am sending it to you since if speaks to children and the taking of aspirin while suffering from the flu (or any other viral or bacterial infection).
The bottom line is be very careful in administering aspirin to children.
Others:
https://www.sciencedaily.com/releases/2009/10/091002132346.htm
https://www.nytimes.com/2009/10/13/health/13aspirin.html
https://www.reddit.com/r/conspiracy/comments/aapsfe/bayer_death_and_the_1918_spanish_flu_epidemic/
https://academic.oup.com/cid/article/49/9/1405/301441
There are many other articles that go into more detail.