Israel on Thursday began administering doses of coronavirus vaccines tailored to fight the highly infectious omicron variant as its health authorities urged at-risk groups and those over 65 to get the shot.

The rollout of the new vaccine follows Israel’s world-leading drive to vaccinate its population early in 2021. Health officials are now voicing growing concerns about increased COVID-19 infections in the upcoming winter.

Arsen Arutiunian, an official with the Israeli healthcare provider Clalit, said that there had been “big demand” for the booster since the new campaign began. He said the clinic has been flooded with phone calls from people of all ages looking to schedule an appointment.

“I received all of the previous vaccinations. So far, touch wood, I haven’t been infected even though my entire family has I’ve somehow become Teflon. And as they say, keeping healthy,” said Eytan Gurfinkel, a Tel Aviv resident.

As of Thursday, 95 people were hospitalized with serious cases of coronavirus — the lowest point since May. Over 11,600 Israelis have died of COVID-19 since the start of the pandemic in early 2020, according to Health Ministry statistics.

Israel was a world leader last year in vaccinating its population of 9.5 million against the coronavirus, after it struck a deal with Pfizer to trade vaccines for medical data. It quickly vaccinated over 60% of its population with at least two doses of the Pfizer/BioNTech vaccine by last fall.

Over 4.5 million Israelis have received a third dose of the Pfizer/BioNTech vaccine, but just over 800,000 have taken a fourth shot.

In August, the FDA approved updated COVID boosters that target the omicron strain and U.S. health officials are beginning the rollout this fall.

(AP)