So after successfully containing the virus for months, the impoverished half-island nation is counting down the days until its first batch of COVID-19 vaccines arrive.

The former Portuguese colony this week announced that a national immunisation plan had been approved, with vaccines set to arrive at the start of the second quarter under the international vaccine-sharing program COVAX.

With no known community transmission and all 102 of its infections imported, East Timor has among the world's lowest number of cases, a record under constant threat from neighbouring Indonesia's unrelenting wave of more than 1.2 million infections, which have caused over 33,000 deaths.

"The greatest threat of virus introduction or of a surge of cases is certainly from across the land border," said Arvind Mathur, the World Health Organisation's East Timor representative.

"One of the important, successful interventions I would say has been a very excellent border control."

In the latest such measure, the government announced on Monday a "health fence", restricting movements in several border municipalities until March 3.

Under COVAX, East Timor will receive free access to vaccines, likely the AstraZeneca-produced shot, for 20 per cent of its roughly 1.3 million population, giving a preemptive boost for its fragile health system.

The first phase will reach 8 per cent of the population, including health workers, airport staff and people in border areas.

Inacio Santos, director of the Bairo Pite health clinic in the capital Dili, said authorities had taken strong early action by declaring a state of emergency last March, then introducing rigorous quarantine, testing and tracing.

"We are lucky we don't have community transmission," Santos told Reuters.

"As healthcare workers we are very worried that if there is local transmission then we won't have sophisticated equipment, we do not even have proper PPE (personal protective equipment)".

Across the 228km border is the other half of Timor island, which is part of Indonesia, from which East Timor gained independence in 2002 after a violence-plagued vote three years earlier.

Timorese families continue to live on either side of the border, with illegal crossings not uncommon.

WHO representative Mathur said East Timor had done a good job so far in keeping the virus at bay.

"COVID-19 could have been actually a true disaster had it not been for the ministry of health that acted swiftly, enabling the country to contain the outbreaks so far so effectively and efficiently," Mathur said.

Australian Associated Press