It’s true that these cases are all of adults, and the recent outbreak is among children between one month and 16 years old. It’s also true that there has been no definitive link established between mRNA vaccine and liver damage, and even if there were a definite cause, this is a tiny handful of cases among millions and millions of mRNA shots.
However, these articles are all from 2021. The possible danger of severe liver disease from mRNA vaccines was being considered a year ago. Perhaps in the absence of the usual suspects that cause autoimmune hepatitis, and the presence of cases where AIH developed after the vaccine, the danger of AIH being a rare side-effect of mRNA vaccination needs to be more thoroughly studied now that so many children are suddenly coming down with severe liver disease for no apparent reason.
There are no COVID vaccines authorized for children under 5. Furthermore, there are no vaccines even being investigated for children under the age 6 months.