Please explain, then, why it doesn't have full approval. You likely know there are both safety problems and efficacy problems, as well as concerns about long-term effects.I said it before that it's all relative. If initial immunity from vaccines still lasted then we would be saying we don't know how long vaccine immunity lasts. You are not making a fair comparison.
And just because it hasn't met the standards of full approval doesn't indicate what we do and don't know.
As it turns out, the 'vaccines' do little to prevent infection, and the 'vaccine' benefits are short term. It is much more accurate to call them 'therapeutics' than 'vaccines.' Both Pfizer and Modern admitted in their application for emergency use they didn't believe the 'vaccines' would significantly reduce infections or transmissibility of Covid. They only claimed the 'vaccines' would reduce hospitalizations and deaths.
Natural immunity, by comparison, is already demonstrated to be far superior to the 'vaccines' in every way. But it's just been the last 2-3 weeks that any of the major health organizations have even acknowledged natural immunity. Even then it's usually to dismiss it or to say "natural immunity has some benefit but you still "need to be up to date with your vaccinations."