In Israel, more than half (5.3 million) its residents have been vaccinated and an additional 830,000 people have tested positive for the virus in the past, which should give them some natural immunity. That works out as roughly 68% of the population who are likely to have antibodies in their blood which can fight off the virus. Prof Eyal Leshem, a director at Israel's largest hospital, the Sheba Medical Center, said herd immunity was the "only explanation" for the fact that cases continued to fall even as more restrictions were lifted. "There is a continuous decline despite returning to near normalcy," he said. "This tells us that even if a person is infected, most people they meet walking around won't be infected by them."