A third COVID-19 vaccination shot appeared to significantly curb a delta-led surge in cases and prevent severe illness, according to a study in Israel, the first country to offer boosters to seniors.
Twelve days or more after a booster dose of the vaccine made by Pfizer Inc. and its partner BioNTech SE, the risk of a confirmed infection decreased more than elevenfold relative to people given only two shots, researchers from Israel’s Ministry of Health and key scientific institutes found. A third dose was associated with at least a tenfold reduction in the risk of falling seriously ill, according to the research released Friday.
The more-infectious delta variant has fueled a resurgence of COVID-19 cases and hospitalizations in many countries, including Israel, prompting plans to administer extra doses to those already immunized. Israeli authorities approved a Pfizer-BioNTech booster shot for vulnerable citizens on July 12 and began offering it on July 30 to all people 60 or older who had been immunized for at least five months. On Sunday, the government expanded the booster drive to all residents age 12 and above.