TEL AVIV (Reuters) — Israel’s coronavirus vaccination campaign, the world’s fastest per capita, shifted to booster shots on Sunday in a bid to protect the most vulnerable citizens by next month and ease curbs on the economy.

Israelis over the age of 60, those with health problems and medical personnel have been receiving their first injections of Pfizer Inc. vaccines since Dec 19. As three weeks have passed, they are beginning to be due for follow-up, final doses.

“It changes everything,” said Guy Chosen, a director of the COVID-19 ward at Tel Aviv’s Ichilov Hospital, who got his second injection. “I’m really happy that I’m over that (and) looking forward for all this epidemic to be finished.”

The Health Ministry said 19.5% of the population have been vaccinated, including more than 72% of the over-60s. Latecomer elderly will be admitted for first shots, officials say, but otherwise, vaccines will be reserved for boosters.

Israel’s vaccination rate is by far the fastest compared to the rest of the world, according to the Our World in Data website, which is run by research organization Oxford Martin School.

In second place is the United Arab Emirates, which as of Sunday had inoculated 10% of its population, followed by Bahrain and the United States at 5% and 2%, respectively.

Prime Minister Benjamin Netanyahu has said vaccinating vulnerable cohorts will allow Israel to emerge from the pandemic in February. He is up for reelection in March.

Israel has in parallel tightened a lockdown to rein in a spike in coronavirus cases. Officials say public over-confidence in the vaccines may have led to laxity in other precautions and stoked fresh contagions. Hospitals worry about being overwhelmed by patients and personnel being more exposed.

“We have quite a rise in the numbers of medical staff which are infected in the last 10 days – an extreme increase – and we are afraid that we’ll be short of people,” Chosen said.

A week after the booster, each recipient will be issued with a Health Ministry vaccination certificate providing exemption from quarantine, officials say.

Israel last week received an initial shipment of Moderna Inc vaccines which Netanyahu said would be administered at home to those who cannot come to clinics.