BEIJING - China has passed the one billion mark in the number of Covid-19 vaccine doses administered, the country announced on Sunday (June 20). This is more than a third of the total administered worldwide.

In a brief statement, the National Health Commission said that as of Saturday, 1.01 billion doses of coronavirus vaccines had been dispensed. According to a calculation by The Straits Times, some 100 million of those shots were administered in the past five days.

Even as China battles a wave of cases in the southern province of Guangdong, this is a significant step towards reaching Beijing's ambitious goal of vaccinating 40 per cent of the country's population, or about 580 million people, by end-June.

It is unclear how many people have been fully vaccinated, but official figures showed that more than 80 per cent of the capital city's population have been inoculated.

But the country is still lagging behind the United States, Britain and leading European nations, where vaccine coverage is approaching or has exceeded half of their populations, according to Bloomberg's vaccine tracker.

China was one of the first countries to roll out Covid-19 vaccines last December, approving them for emergency use for front-line workers, those in the service industry, as well as cold-chain logistics workers who the authorities said were at risk of infection through surface contact.

The vaccines were later extended to the general population but got off to a slow start after successful containment of the virus meant citizens saw little urgency in getting vaccinated.

In recent months, the authorities have ramped up efforts through a mix of soft and hard power.

Shenzhen officials created a slogan that punned a popular song about cats - the Chinese term for vaccines, yi miao, sounds like a cat's meow; the authorities in Anhui province offered free eggs at mobile vaccination stations deployed across the country.

But some in the food and beverage industry were told that they would not be allowed to work unvaccinated, while those who had not had jabs were barred from attending certain government events.

The health authorities have not said when they expect China to reach herd immunity.

A recent outbreak of the more contagious Delta variant of the virus in Guangzhou and Shenzhen have also pushed many to get vaccinated - the country reported 23 new coronavirus cases on Sunday.

Most of the country's conditionally approved vaccines have published efficacy rates that are behind those of rival shots by Pfizer-BioNTech and Moderna, whose success rates are 95 per cent and 94 per cent, respectively.

Sinovac previously said trials of its shot in Brazil showed around 50 per cent efficacy in preventing infection and 80 per cent in preventing cases requiring medical intervention. Singapore's Health Sciences Authority has not approved the jab to be part of the national vaccination programme, but it is available through a special access route.

Sinopharm's two vaccines have efficacy rates of 79 per cent and 72 per cent, respectively, while the overall efficacy for CanSino's shot stands at 65 per cent after 28 days.

Three of China's four vaccines available to the public require two doses.

According to officials, China is expected to produce more than three billion vaccine doses this year, but it is unclear what proportion will remain for domestic use. Beijing has promised hundreds of millions of doses to various countries through a series of bilateral efforts.

The addition of the Sinopharm and Sinovac shots to the World Health Organisation's emergency-use list means they can now be part of Covax, a global effort to ensure equal vaccine access.