growstuff
Unfortunately, the situation is more complicated than that. It is probably true of primary school children, but not of secondary age children, for whom the Pfizer vaccine is licensed.
Not only that, but it appears that immunity acquired by infection might not be strong enough to prevent further infection and might lead to autoimmune deficiencies later. There have been reports of children suffering long Covid even after only having mild symptoms or being asymptomatic.
Research is ongoing. At the moment, the disease hasn't been around for long enough to know what the long term effects will be. Many scientists and medics think that we're storing up problems for the future. The UK is falling behind with vaccinating over 12 year olds.
PS. I read Ladhani's tweets.
PPS. It would appear that the country has a supply problem with the Pfizer vaccine. We've used up (or allocated) the 40 million doses we initially ordered. Pfizer has promised more doses in the autumn and it wouldn't surprise me at all if there's a u-turn on vaccinating teenagers, by which time many will already have been infected.
I cannot speak to the wider data on infection and subsequent immunity gathered by governments and scientific bodies.
I can tell you that I had it twice, confirmed by test on both occasions, once in first lockdown, and the second time after first vaccination but before second.
I was notably ill on both occasions, although not hospitalised. I have significant new immune system related diseases diagnosed since my first episode.
My experience may not be the mainstream one, but certainly my personal immune system did not view Covid as a one-and-done deal and I have absolutely no faith that I will not get it a third, fourth or fifth time.
I know I can be a right [expletive] about vaccines etc, but my newly damaged heart and lungs really do not want to get Covid any more times than strictly necessary.