South Korea aims to secure a supply of novel coronavirus vaccines for 30 million people, or 60% of its population, Prime Minister Chung Sye-kyun said on Tuesday.

While authorities would like to inoculate the entire population of 52 million, uncertainty around any vaccine`s safety, efficacy and development was limiting South Korea`s investment, Chung told a cabinet meeting.

Global vaccine makers are racing to develop an effective vaccine against the virus that has killed more than 925,000 people since it emerged in China late last year.

Chung said the government would negotiate with relevant international organisations and vaccine makers to secure the supply and would buy more as developments unfolded.

In August, South Korea said it planned to join the COVAX facility, a global novel coronavirus vaccine allocation plan co-led by the World Health Organization (WHO), which aims to help buy and fairly distribute the shots.

South Korea will buy 20 million doses of vaccine from the COVAX scheme, enough for 10 million people, and 40 million doses from private drug-makers, health authorities said in a statement.

The government has prepared 172 billion won ($146 million) to pay for vaccines, including $70 million for the 20 million doses from the COVAX facility.

“We will prepare to secure the safest and proven-effective vaccines as of now to inoculate as many as possible,” a Korea Disease Control and Prevention Agency (KDCA) official, Kwon Jun-wook, told a briefing.

South Korea has been one of the world’s coronavirus mitigation success stories, with an aggressive testing and tracing strategy, but it has nevertheless been battling persistent spikes in infections.

The KDCA reported 106 new coronavirus cases as of Monday, bringing its total number of infections to 22,391 with 367 deaths.

South Korea’s SK Bioscience in July agreed to manufacture AstraZeneca’s experimental vaccine, which has shown promise, to help the British company build global supplies.

Novavax Inc last month separately said SK Bioscience, a unit of SK Chemicals, would manufacture a component of the US drug developer`s experimental coronavirus vaccine in a bid to boost its supply.