If I'm reading this correctly, this is "protection against severe disease" and has little to do with transmission. The National Airport Data from Israel seems to suggest "the absolute number of infected individuals in the Vaccinated (boosted) group is likely to be at least as high as in the Unvaccinated" [0] So it seems to me that as long as we all remain obsessed with case numbers and not actual hospitalizations and…
It's looking like high double and triple vaccination rates can do it (like 80%+), but that's starting to look impossible in some countries.