I don't think I personally used “herd immunity”. We used different benchmarks of vaccination to inform the next sets of policies and what we could expect over the summer or in the fall, for instance, with a higher vaccination rate with two doses. Of course, with the appearance of the delta variant and then the omicron virus, these are moving targets.
I think many experts believe that the so-called herd immunity may not be achievable with this virus because it undergoes constant evolution, so what you're looking at is this endemic state in which people will get reinfected over time as immunity wanes and then it would also be determined by the appearance of variants that may invade the immune system as well.
I think that is the reality. It is going to be more like an endemic virus.