JERUSALEM, Israel -- Israelis aged 40 and over will be able to receive coronavirus vaccine booster shots starting this weekend, Health Minister Nitzan Horowitz said Thursday, as the country battles a spike in infections.

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 vaccine doses in exchange for sharing data on their effectiveness.

The inoculation campaign was hailed as a success story that helped drastically reduce infections in the country of nine million.

But cases have been rising due to the spread of the Delta variant among the unvaccinated and waning immunity in others.

To try and contain the spread, authorities last week began administrating a booster shot to those aged 50 and older, after starting a campaign for over-60s late last month.

Horowitz, who is among those who have received a third dose, tweeted Thursday that people aged 40 and over will be able to get a booster shot from Sunday.

''We have vaccines for everyone and now those 40 and older can receive a third dose,'' he wrote. ''The vaccine is effective. Let's stop this Delta.''

Israel has recorded more than 970,000 coronavirus infections since the pandemic started early last year, and over 6,700 deaths.

More than 5.4 million people have received two doses of the vaccine, while 1.2 million have had a third jab.

Earlier this month, the World Health Organization called for a moratorium on COVID-19 vaccine booster shots to help ease the drastic inequity in dose distribution between rich and poor nations.