Singapore and Hong Kong are in "close discussions" on the suspended air travel bubble for leisure travel without quarantine, as the Covid-19 situation in Hong Kong appears to be easing.
The arrangement between the two sides had been suspended indefinitely since Nov 21 last year, the eve of its planned launch, after a spike in the number of coronavirus cases in Hong Kong.
Both cities had earlier agreed that the travel bubble would be suspended if the seven-day average of unlinked cases in either city exceeded five.
When the plan was put on hold, Hong Kong's rolling seven-day average of unlinked cases was 3.86.
It shot up to 16 by the end of November and continued to remain above the stated threshold.
But in the past week, the figure dipped below five. It stood at 4.57 as at Friday.
In response to queries about the impact of the improving Covid-19 situation in Hong Kong, the Civil Aviation Authority of Singapore said talks are ongoing.
Its director of air transport Daniel Ng said more details will be announced when they are ready.
Dr Leong Hoe Nam, an infectious diseases specialist at Mount Elizabeth Novena Hospital, said it would be safe to start the air travel bubble if the number of unlinked cases remains below five consistently for two to three weeks.
This is taking into account that the incubation period of the virus has been lengthened to almost 21 days, he added.
"As an added precaution, they should ask the individual to be vaccinated. The incentive then should be no Covid-19 polymerase chain reaction (PCR) testing will be done," Dr Leong added.
"Vaccination of travellers can expedite the formation of travel bubbles in a safe manner."
Transport Minister Ong Ye Kung said last month that he would rather not set a target on when the air travel bubble can begin.
Under the original arrangement, people travelling between Singapore and Hong Kong can avoid a lengthy quarantine by taking multiple Covid-19 tests.
Both sides agreed to having one flight a day into each city and a quota of 200 travellers per flight.
There were no restrictions on the purpose of travel, and no need for a controlled itinerary.
But travellers are required to meet eligibility criteria, such as staying in either city for 14 consecutive days prior to departure, and adhere to border control measures and public health requirements of both cities.
While Hong Kong had imposed stricter restrictions in the past few months, it relaxed social distancing rules in the past week, for the first time since November.
It will start its mass vaccination drive this week.
Hong Kong reported 15 new Covid-19 infections yesterday, taking its tally to 10,848.
Aviation analyst Brendan Sobie from Sobie Aviation said he hopes the air travel bubble can take off either in Singapore or elsewhere.
He added: "Overall, borders won't reopen that quickly even with the vaccines. Air travel bubbles are needed to facilitate partial recovery in the meantime."
Mr Aaron Wong, founder of frequent flier website MileLion, is confident that there will be strong demand should both cities proceed with the plan.
"We are fast approaching the one-year mark (March 15) since the Ministry of Health issued a blanket advisory against all non-essential travel worldwide," he said.
"Singaporeans are a travel-loving bunch in general, and all that demand needs an outlet."