Israelis aged 50 and over began receiving vaccine booster shots against the coronavirus Friday as part of a government bid to stem spiking infections driven by the Delta variant.
The government announced on Thursday that it was offering third shots to people aged over 50, two weeks after launching a campaign to give the elderly booster jabs.
"This is an important step in the fight against the Delta pandemic," Prime Minister Naftali Bennett said in a statement.
Israel was one of the first countries to launch a vaccination drive in mid-December via an agreement with Pfizer to obtain millions of paid doses in exchange for sharing data on their effectiveness.
The campaign helped to drastically bring down infections, but that trend has since reversed, driven by the spread of the Delta variant in unvaccinated people as well as those whose immunity has waned six months after they got their initial shots.
"Starting this morning, people between the ages of 50 and 60 have been vaccinated at Clalit clinics across the country," said Ran Balicer, chief innovation officer at Clalit Health Services and the chairman of Israel's national expert panel on COVID-19.
"We have hope this vaccination campaign will help reduce the impact of the ensuing surge of COVID-19 infections on the severe illness among the groups that are most vulnerable," he told AFP.
The World Health Organisation has called for a moratorium on booster shots until at least the end of September in order to address inequalities in global dose distribution.
But Bennett has said Israel is doing the world a "great service" by administering booster shots.
So far more than 770,000 Israelis have received a third shot, according to the health ministry.
Although the US Food and Drug Administration, which Israel generally follows, has only approved third shots for the immunocompromised, Bennett said experts guided him in lowering the age.
"Members of the team worked diligently, professionally and thoroughly, and reached the conclusion that the third inoculation for people aged 50 and over, and for medical teams, is effective and correct," Bennett said in Thursday's statement.
Health Minister Nitzan Horowitz, 56, said he planned to get his booster shot on Friday.
Public health expert Nadav Davidovitch, who advises the government's pandemic response team, said rising cases were adding a sense of urgency to the campaign to vaccinate all Israelis.
"We can't reach a lockdown. A lockdown in my eyes is a failure," Davidovitch told army radio.
Israel's health ministry said Friday it had recorded 6,083 new cases the previous day.