According to Israeli Prime Minister Naftali Bennett, a fourth dosage of COVID-19 vaccine raises antibodies five-fold a week after the injection is given, according to early findings of an Israeli research.

“A week into the fourth dosage, we know with a better degree of assurance that the fourth dose is safe,” Bennett said at Sheba Medical Center, where second booster injections are being given in a study among its employees amid a statewide outbreak of Omicron variant infections.

“The second piece of news is that we detect a five-fold rise in the amount of antibodies in the vaccinated individual a week after administration of a fourth dosage,” he told reporters.

“This most likely means a significant increase against infection and … hospitalization and (severe) symptoms,” Bennett said in English.

Israel has played a leading role in studying the effects of COVID-19 vaccines, as the fastest country to roll out two-dose inoculations to a wide population a year ago and one of the first to give third shots as boosters. It is now administering fourth doses of the Pfizer/BioNTech vaccine to people over 60, health workers and immunocompromised patients.