BEIJING (BLOOMBERG) - China's staunch defence of its Covid-zero policy has meant the country won't join the global pivot toward living with the virus anytime soon. But authorities won't cling to their unwavering adherence to that approach forever either.

The rigid strategy, which has pummelled the world's second-biggest economy, disrupted supply chains and brought the lives of millions in many mainland cities to a miserable standstill, has been undergoing minor adjustments as the virus mutates.

Its eventual dismantling, however, will be gradual, involving step-by-step easing rather than a sudden end to all curbs in one fell swoop, experts say.

Though the government is ramping up the rhetoric on how it won't back down from aggressive and sweeping curbs - ranging from mass testing and lockdowns to contact tracing and border restrictions in the near term - officials have also started talking about what it would take to claim "triumph" over Covid-19.

These are the signposts to watch for, which may indicate China is exiting its Covid- zero policy:

Shift in rhetoric

A change in how Covid-19 is described in official media, government communication and domestic public health debates would precede any major shift in coronavirus-related policies, according to several experts.

That would require a marked departure from the current emphasis on how the pathogen is a bigger danger than the one that causes the seasonal flu, with top advisers and state media frequently labelling the idea of living with the virus as "wrongful".

That contrasts with former Covid-zero adherents like Singapore and Australia, where governments now emphasise that the virus is not a threat if one is vaccinated.

"We would want to see when the government can communicate to the public about the risk of the virus in a balanced, objective and fair fashion," said Dr Huang Yanzhong, a senior fellow for global health at the New York-based Council on Foreign Relations.

When government rhetoric shifts to highlighting Omicron's milder nature compared to the original strain and its significantly lower fatality rate, along with an open discussion on how to live with it, "that would be a very key signal" that would show "authorities are looking for a down-ramp", Dr Huang said.

Legal status

Under China's existing infectious disease law, Covid-19 is grouped with Aids, viral hepatitis, bird flu, rabies and several others as a Class B communicable disease. But the legislation also calls for stringent containment measures reserved for the riskiest and most severe infectious diseases such as the plague and cholera.

"That entails the highest grade of control, obliging administrative and legal departments to wield tremendous power to eliminate the virus," said Dr Chen Zhengming, an epidemiology professor at the University of Oxford. "The way to deal with Covid needs to be adjusted, but it will be hard to do so without downgrading Covid in the country's infectious disease control law," he said.

Some Asian countries, which like China justified aggressive containment with legislation, have already changed tack. For instance, early during the pandemic, South Korea placed the disease on par with Ebola and Middle East Respiratory Syndrome, or Mers, as a top risk disease. Later, it moved it to a lower category that also includes tuberculosis and cholera, enabling the removal of almost all social distancing curbs by mid-April.

Despite its greater transmissibility, Omicron's milder nature raises hope that the virus is evolving into a relatively more benign pathogen. An even milder variant could help China eventually reopen, Dr Chen said, adding it could happen some time later this year or early 2023.

Yet determining whether a new variant will indeed cause less harm in China could be tricky, because milder symptoms observed around the world could "stem in part from the pre-existing immunity from both vaccination and widespread infections," he said. "But in China, natural infection is still very low."

Elderly vaccination

Covid-zero's early proponents from Singapore to Australia and New Zealand have all sought to make sure their most vulnerable groups - the elderly and others with weak immune systems - have acquired protection through vaccination before easing and opening up.

China will need to do the same to avoid mass outbreaks and death when it opens up. The country's Covid-zero policy could only start to materially loosen once the vaccination rate for people aged 80 and above reaches 80 per cent, according to Mr Ding Shuang, chief economist for Greater China and North Asia at Standard Chartered.

In March, the National Health Commission said only half the people in China aged 80 and above had been fully vaccinated, making the remaining seniors vulnerable to greater risk of death after infection, as evidenced by outbreaks around the world.

In comparison, Singapore achieved about 90 per cent rate for the same age group before starting to open up. In Shanghai, only 15 per cent of people over 80 have had two shots, the China Daily reported last month.

Health officials have started campaigns urging the elderly to get vaccinated.

Antivirals, mRNA shot

Dr Liang Wannian, an epidemiologist who has led China's coronavirus response since day one, told reporters last month that adhering to Covid-zero buys time for China to accelerate development of antivirals and vaccines. His comments suggested that Omicron's mortality risk, which is higher than influenza, is still too high for China to accept.

That means, if China gets sufficient supplies of antivirals, either Pfizer's Paxlovid or any effective, approved homegrown alternatives, the country would have enough arsenal, in Dr Liang's words, to "vanquish Covid".

Another big development to monitor, according to Oxford's Dr Chen, is to see if China will approve BioNTech SE's long-pending application for its mRNA vaccine co-developed with Pfizer.

Though Shanghai Fosun Pharmaceutical Group has won mainland distribution rights, some analysts have said the delay in authorisation for more than a year is due to the government's reluctance to greenlight a foreign vaccine.

Shorter quarantine

Cutting the duration of mandatory hotel quarantine for incoming travellers from 14 days, or allowing those who tested positive to start isolating at home instead of hotels or government facilities, would be a clear sign of easing, according to Dr Huang.

A total of eight cities, including Shanghai, are currently in the midst of a month-long pilot programme that allows people arriving from overseas and close contacts of infected to quarantine only for 10 days.

Oxford University's Dr Chen previously suggested that authorities could try relaxing many restrictions in small areas such as border towns prone to frequent infections.

While authorities don't tolerate public debate over easing, that doesn't mean they aren't considering some steps, said Standard Chartered's Mr Ding.

Similarly, if the country starts making it easier for those who are fully vaccinated or have received boosters to enter, it could indicate Beijing "is shifting more toward protecting high-risk groups rather than enacting sweeping curbs", Dr Chen said.

Ideology, timing

Some say the signs of easing may start to emerge most likely after a key Communist Party summit later this year, where President Xi Jinping is expected to secure an unprecedented third term as China's paramount leader.

After showcasing how Beijing's approach to containing the coronavirus is superior to that of the West for about two years, Mr Xi's credibility is now inextricably linked to the success of his Covid-zero strategy. Abandoning it too soon would be politically risky, especially when he's seeking an extended tenure.

"If zero-Covid is essentially a political tool, then, we should expect no significant easing until well after the party congress later this year and perhaps not until 2023," said Mr George Magnus, a research associate at Oxford's China Centre. "Xi's personal association with zero-Covid makes it important that the policy as such endures."

Mr Frank Tsai, a lecturer at the Emlyon Business School's Shanghai campus and founder of consulting firm China Crossroads, said easing could only be justified once the government overcomes ideological hurdles.

"After saying for two years that Covid control makes China better than the West, the party can't easily walk back its proposition that this is a competition of ideologies," he said.