The good news is that now it looks like there's a light at the end of the tunnel. Isarel, with around 60% vaccinated, is showing great results:
It depends on the type of vaccine. In Israel, they mostly used the Pfizer-BioNTech vaccine and it is very effective in preventing COVID. On the other hand, Seychelles also had 60%+ vaccination rate, but they used the vaccine from Oxford-AstraZeneca. Seychelles is undergoing a second wave of the pandemic right now (same with Maldives, another country which had more than 60% vaccination rate with AstraZeneca). Now the extreme case is that of Chile, which had more than 50% vaccination rate with the Chinese vaccine Sinovac. But the infection rates seems to have increased after the vaccination.