Cases of contagion and serious illness "substantially" drop with the third Pfizer dose.
This is underlined by a study published in the New England Journal of Medicine, based on data from the Israeli health ministry.
The infection rate, he notes, at least 12 days after the 'booster', is "11.3 times" lower than the two doses while "the severe disease rate is 19.5" times lower.
The study was conducted from 30 July to 31 August on 1.13 million over 60s who had completed immunization 5 months earlier, divided into two groups: those who received the third dose and those who received two.