I'm one that believes that there will not be a long term vaccine for Covid-19. We will need to get a shot every so often, at best, similar to the flu shot every year. Given the potential deadliness of the disease working from home will be here until we come up with a cure or a way to control it.
Will WFH be here forever? Probably not but it will be here for most of the working life of most people living today.
I also think that it will evolve into something different than the way it works now. Most people can't work from home and deal with the distractions. Something different will evolve but I don't really know what. Maybe something like WeWork but offices that can be disinfected on a per user basis.