A fourth dose of the COVID-19 vaccine provides people people aged 60 and up with three times as effective protection from serious illness, according to a new scientific study.
Published in the peer-reviewed academic periodical The New England Journal of Medicine, the study was written by several Israeli authors - including Health Ministry Director-General Prof. Nachman Ash and head of Public Health Services Dr. Sharon Alroy-Preis - and relied entirely on Israeli Health Ministry data from the roll-out of the fourth vaccine dose at the beginning of 2022.
Israel had begun administering the fourth COVID-19 vaccine dose to Israelis aged 60 or older on January 2. This coincided with the arrival of the Omicron variant of SARS-CoV-2, the novel coronavirus that causes COVID-19.
However, around four months later, the effect the fourth dose has had on preventing severe illnesses brought about by infection had yet to be studied.
Based on this data, those age 60 and over who received four doses were three times more protected from severe illness than those who received just three doses.
These findings reflect prior studies by Israeli health funds and the Health Ministry regarding the effectiveness of the fourth dose in protecting against severe illness.
Back in January, a Health Ministry report found that the fourth dose protected people aged 60 and up from severe illness three times as much and from infection twice as much compared to those who just received three doses.
A study in March published in The New England Journal of Medicine, however, found that the fourth vaccine offers little to no protection compared to three doses in young and healthy individuals. Regarding symptomatic infection, it did provide some protection, but it was moderate.
A study by Clalit Health Services from early April, however, found that the fourth vaccine resulted in a 78% decrease in COVID-19 related deaths in adults aged 60-100.
Shira Silkoff contributed to this report.