I believe many hospitalizations, especially from during June, July and August, were from pre-delta, i.e. caused by covid classic or alpha variant on which vaccines indeed work to a high degree. But our data is so messy and not transparent at all. It's hard to argue that this moment. But, the bottom line is, from the very beginning of pandemic until now, more 90% of infected are mild, don't need to be hospitalized. Our human immune system are the best "vaccine" in term of efficacy, responsible for 90% un-hospitalization.