The application of the fourth dose of vaccine against the coronavirus is "safe" and produces five times the antibodies, said Israeli Prime Minister Naftali Bennett on Tuesday, when visiting a hospital that carried out a study on the matter.

Bennet said that administering the fourth dose to 154 employees at Sheba Hospital, near Tel Aviv, demonstrated that the procedure "works."

"One week after the fourth dose, we know with a high level of certainty that the fourth dose is safe," he said with Professor Galia Rahav, head of Sheba's infectious diseases unit and director of the study.

"One week after the administration of the fourth dose, we observed that the number of antibodies in the vaccinated person quintupled," he added.

"This probably means a significant increase in protection against infection and against hospitalization and severe symptoms," he continued, noting that the center will publish its findings shortly.

On Friday, Israel began administering the fourth vaccine to people with weak immunity and on Monday it expanded this measure to health workers and people over 60, becoming one of the first countries to do so.

The country has registered more than 1.4 million cases of Covid-19 infection, including 8,247 deaths