Israel on Sunday (Aug 29) began offering a COVID-19 booster to children as young as 12, and its prime minister said a campaign that began a month ago among seniors has slowed a rise in severe illness caused by the Delta variant.

Announcing the decision, top Israeli health officials said the effectiveness of the second dose of the Pfizer-BioNTech vaccine waned six months after administration, making a booster necessary.

“Starting today, the third vaccine dose is open to all”, - said Health Ministry Director General Nachman Ash, referring to the Pfizer vaccine.

The effect of the initial two vaccine doses weakens after five months and therefore, people who were inoculated more than five months ago should get a booster, ministry officials said in a press briefing broadcast online.