A study of some 40,000 elderly Israelis shows that the fourth COVID-19 vaccination reduced coronavirus death rates among the most vulnerable Israelis by 72%. It also slashed infection rates in that population by 60% and hospitalizations by 34%.

https://www.timesofisrael.com/major-israeli-study-elderlys-covid-death-slashed-by-72-after-4th-vaccine/