IMO, you guys are arguing about re arranging the decks chairs. Any vaccine that reduces infection for even 40%? of the population, will have a huge positive overall effect, its just if we want to effectively stop COVID in its tracks, and reduce masking wearing, a vaccine(s) needs to be up to over 70% efficacy. How many vaccines will we have try out to get to 70%?, I have no idea, but it should be possible, if we can hold out that long and tolerate the deaths and costs it takes to get there. There is no silver bullet here.