China's drug authorities have given "conditional" approval for a second Covid-19 vaccine, Sinovac's CoronaVac jab - but the country could still be waiting until 2022 to reach herd immunity.
The vaccine has already been rolled out to key groups at higher risk of exposure to coronavirus but yesterday's approval allows for its use on the general public.
Fellow Chinese pharmaceutical company Sinopharm received a similar conditional green light in December to put its vaccine on the market.
Chinese vaccine makers have chequered reputations, after major scandals at home involving expired or poor quality products.
Despite being the first to start administering shots, China risks falling behind in the global race to vaccinate against the coronavirus, a process that could take years in the world's most populous nation.
Authorities in China began giving vaccines last June before clinical trials concluded, targeting groups deemed at risk – military, border officials, medical staff. Since then, 22.8 million doses of Covid-19 vaccines have been dispensed.
But that's a drop in the bucket for a country of 1.4 billion people. China's immunisation programme could stretch until late 2022, given the "sheer size" of its population, according to a study by the Economist Intelligence Unit.
Countries like the US and UK, still ravaged by coronavirus, could actually reach herd immunity before China, getting to a point where enough of the population is immune that the virus has nowhere to go – roughly 70 per cent.
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"Mass vaccination efforts in the West could be bad news for China's leaders," said Yanzhong Huang, a senior fellow for global health at the Council on Foreign Relations.
"If Western countries achieve herd immunity ahead of China, and China, in order to maintain its [containment] success, needs to continue draconian stringent Covid control policies [and] lockdown measures – that would make China look bad."
Such an "immunity gap" could risk a resurgence of coronavirus and spell a downturn for the Chinese economy, especially if much of the world is able to resume normal life sooner.
For China, reaching herd immunity will require relying on mass vaccinations. Success in containing Covid-19 – clocking a few dozen infections a day – means much of the country's population has not been exposed to coronavirus and remains highly susceptible to infection.
Countries still battling coronavirus, however, can get there with a mix of inoculations and natural immunity.
But social distancing, mass testing and quarantines have been so effective that there's little urgency to "vaccinate at a fast speed," said Xi Chen, an associate professor at Yale University's School of Public Health.
Still, those measures are a temporary defence. Testing, for instance, only gives a patient's current status, whereas a "vaccination campaign will help you protect the population for a longer time period," he said.
Another issue is the fact that China is not administering vaccines to people over the age of 60, a group at high risk of contracting coronavirus given a lack of data on how the shots would affect the elderly.
That's because clinical trials were largely designed to test Chinese vaccines on younger subjects, a choice experts surmise was made to yield better test results as seniors – with potentially more health complications – could skew data unfavourably.
In a best-case scenario, Huang estimates China could accomplish herd immunity by inoculating at least 66 per cent of the population, or 924 million people – nearly 14 times the size of the UK's population – and if vaccines given have an efficacy rate of 91 per cent.
But that's the highest rate ever reported by Sinovac in a trial in Turkey – not all Chinese vaccines could end up being that effective.
As most Covid-19 vaccines require a two-shot course, that would mean disseminating 1.85 billion doses, more than the country's production capacity for this year of about 1.8 billion.
There are already signs that China is struggling to produce enough vaccines to meet demand.
Some residents in Wuhan such as taxi drivers and chauffeurs – prioritised to receive vaccines given their line of work – told the Telegraph that they have been waiting for their shots since last June.
Countries including Brazil and Turkey have complained of delays in the delivery of doses and active ingredients to produce vaccines locally.
China, eager to use vaccine diplomacy to deflect global anger over its early mistakes in the pandemic, had previously signed contracts with a number of countries to export 800 million vaccines.
But experts say the slowdown in sending doses abroad points to a shift toward satisfying a growing domestic need.
In December, China even bought vaccines – 100 million doses of the vaccine co-developed by US firm Pfizer and Germany's BioNTech.
Syringes and needles in short supply could also create a bottleneck. Producers are rushing to meet domestic and international orders as nations ramp up their immunisation campaigns. Eighty per cent of the world's syringes and needles come from China, according to state media.
But even if China does manufacture enough, the question remains whether the public will choose to receive a vaccine, if it isn't mandatory.
China has so effectively contained Covid-19 that the risk of contracting infections appears minimal, giving people a "false sense of safety," said Mr Huang.
Some think that there is no "need to take the vaccine because if we are safe, if there is a low risk of getting infected, why bother?"
"I think the possibility of getting infected in mainland China now is so low, even lower than having a car accident," said Liu Yizhou, 32, who hasn't gotten a vaccine.