One-third of Israel’s seniors — about 420,000 of those age 60 and older — have received a coronavirus booster shot, Prime Minister Naftali Bennett said Sunday, adding that the figure could reach 500,000 by the end of the day.     Bennett announced the progress of the vaccine campaign, which began 10 days ago and uses the Pfizer vaccine, at a Cabinet meeting.     Israel became a vaccination leader early in the pandemic, with about 5.4 million of its population of 9.3 million people fully vaccinated.