JAKARTA (REUTERS) - Indonesia kicked off its Covid-19 vaccine booster programme for the general public on Wednesday (Jan 12), as the world's fourth-most populous nation hit an almost three-month high in cases amid the rise of the Omicron variant.

Elderly and immunocompromised residents, who are being prioritised in the programme, queued up at local health centres to boost their defences against a virus that has infected more than four million Indonesians.

"I feel safer," said 77-year-old Nurlaeni after receiving her booster on Wednesday morning. "There's more Omicron now, so I feel relieved."

Agreeing, 62-year-old Rosita Wati, also in the queue, said: "For me, for my family, this will protect our health. Our immunity will be better."

The booster shot roll-out comes amid concern about the spread of the Omicron variant in Indonesia, a densely populated country that was hit with a crippling Delta wave in July.

On Tuesday, Indonesia recorded 802 new cases, the highest in almost three months, with senior Cabinet minister Luhut Panjaitan saying that numbers could peak in February.

President Joko Widodo announced on Tuesday that booster shots would be offered free for all those eligible, after initial discussion about charging for boosters sparked controversy.

The booster roll-out, for which the Sinovac, Astra Zeneca, Pfizer and Zifivax vaccines have been approved, is running in parallel with the main Covid-19 vaccination programme.

Indonesia has pledged to vaccinate more than 208 million of its 270 million people, but less than 56 per cent of that target population has received two shots of a Covid-19 vaccine so far, according to health ministry data.

Experts say vaccine hesitancy and logistics in the sprawling archipelago have slowed distribution.

Booster shots in Indonesia will be administered as half doses, in line with studies that confirmed the efficacy of that dosage, said Health Minister Budi Gunadi Sadikin.