Israeli Prime Minister Naftali Bennett receives a third shot of coronavirus disease (COVID-19) vaccine as Israel launches booster shots for over 40 year-olds in Kfar Saba, Israel August 20, 2021. REUTERS/Ronen Zvulun

Israeli Prime Minister Naftali Bennett received a third shot of Pfizer/BioNtech’s COVID-19 vaccine on Friday, after Israel extended its booster campaign for people over 40 to try to curb the Delta coronavirus variant.

New cases in Israel have surged since Delta’s emergence and Bennett, 49, has sought to avoid an economically painful national lockdown by ramping up third doses.

People over 60 began receiving third doses in July, before the minimum age of eligibility was dropped to 50. Health Ministry officials cited waning immunity and Delta’s high infectiousness.

The Health Ministry said on Friday boosters would now be administered to people over 40 whose second shot was at least five months ago. It recommended teachers, health workers, carers of the elderly, and pregnant women of all ages have the shot.

The United States has announced plans to offer booster shots to all Americans, citing data showing diminishing protection. Canada, France and Germany have announced booster campaigns.

“If you go get vaccinated with a third shot, we will be able to avoid a fourth lockdown,” Bennett said before he was shown live on social media receiving his shot. He said Israel would share its data.

Over 1 million of Israel‘s 9.3 million population has received a third shot, which an Israeli healthcare provider said on Wednesday was 86% effective in preventing infection.

Israeli health officials have said they are seeing initial signs that the booster campaign may be slowing the rate at which cases are climbing.

About 1 million eligible Israelis have not taken any dose of the vaccine and severe cases have been climbing, though few fully vaccinated 40 to 50-year-olds have fallen seriously ill.

Studies have shown the vaccine is still highly effective in preventing serious illness but its effectiveness against new infections fell as the Delta variant spread.

There is no consensus among scientists and health agencies that a third dose is necessary.

The World Health Organization said on Wednesday current data did not indicate a need for boosters, and that the most vulnerable people worldwide should be fully vaccinated before high-income countries deploy a top-up.

Pfizer Inc has said its vaccine’s efficacy drops over time and that a third dose showed significantly higher neutralizing antibodies against the initial SARS-CoV-2 virus and the Beta and Delta variants.