Anyway, children getting more seriously ill with those new variant is the least of our worries, the nightmare scenario we don't have to think about because what we have is quite bad enough.
More children getting the virus (no longer protected by a biological advantage with a virus that is now 50 percent better at transmitting anyway) with mean more children becoming ill and needing medical resources.
Whether this is a small proportion of the total number ill is not hugely relevant if that proportion still amounts to a very large number.