Sadly, it isn’t ‘nonsense’ based on what the current definition of long covid actually includes.
This does somewhat depend on where you get your information from. For e.g., this study by Great Ormond Street hospital and UCL from September 2021 has found that 14% of teenagers who tested positive for covid experienced symptoms linked to the virus 15 weeks after infection. That’s at 15 weeks, not up to 15 weeks. Symptoms like headaches, fatigue and loss of smell might seem completely insignificant to you, but a teenager with headaches or fatigue for 15 weeks is not only in pain, but also not able to study to their full potential, they risk missing days of school, which could go on to affect their exam results if it continues, plus they’re not able to go out with friends which can be pretty vital for their mental health at that age. Plus being in pain for 15 weeks. You take them to the doctor who says, effectively, “sorry, we don’t know how to fix this, try watching and waiting.”
Loss of smell also affects taste and being able to eat. Food tastes “wrong”, and some kids stop eating or start to find eating very stressful, which of course is bad for their mental as well as physical health. So you take them to the doctor who again is unable to help (not through any fault of their own!) and you and your child are left to watch and wait.
I’m struggling to think of any parents who would think it’s acceptable for their kids to have to go through that (which is at the minor end of the scale) when it could be prevented or lessened. And it doesn’t help that 14% when infections are low is small and manageable, but 14% when cases are as high as they are in teenagers is, obviously, much higher in terms of actual numbers.
We have longer term data on effects after infection in children compared to effects after vaccination in children?
Well, exactly. And that data shows that serious complications/hospitalisations/PIMS are rare but don’t limit themselves to “only” affecting children with underlying conditions, that long covid is thought to affect 14% of teenagers who test positive for 15+weeks, and that 10,000 children have experienced long covid symptoms for over a year (and imaging that to be a stubbed toe or a bit of a runny nose is another minimising technique). The data on covid’s side doesn’t look hugely appealing, does it.