(This story corrects identity and removes RIC of third company listed in para 5 to China Pharmaceutical Group (Sinopharm), and in para 6 corrects to show Phase 3 trials being conducted outside China) SEOUL (Reuters) - China has provided North Korean leader Kim Jong Un and his family with an experimental coronavirus vaccine, a U.S. analyst said on Tuesday, citing two unidentified Japanese intelligence sources. Harry Kazianis, a North Korea expert at the Center for the National Interest think tank in Washington, said the Kims and several senior North Korean officials had been vaccinated. It was unclear which company had supplied its drug candidate to the Kims and whether it had proven to be safe, he added. “Kim Jong Un and multiple other high-ranking officials within the Kim family and leadership network have been vaccinated for coronavirus within the last two to three weeks thanks to a vaccine candidate supplied by the Chinese government,” Kazianis wrote in an article for online outlet 19FortyFive. Citing U.S. medical scientist Peter J. Hotez, he said at least three Chinese companies were developing a coronavirus vaccine, including Sinovac Biotech Ltd, CanSinoBio and China National Pharmaceutical Group (Sinopharm), an unlisted Beijing-based company. Sinopharm says its candidate has been used by nearly one million people in China, although none of the firms have unveiled results of Phase 3 clinical trial of their experimental COVID-19 vaccines, which are under way outside China. Some experts doubted that Kim would use an experimental vaccine. “Even if a Chinese vaccine had already been approved, no drug is perfect and he would not take that risk when he has numerous shelters which can ensure almost complete isolation,” said Choi Jung-hun, an infectious disease expert who defected from North Korea to the South in 2012. Mark Barry, an East Asia analyst and associate editor of the International Journal on World Peace, said Kim would prefer proven European vaccines to one supplied by Beijing. “The risk is too great. But he’s happy to get Chinese personal protective equipment,” Barry said on Twitter. North Korea has not confirmed any coronavirus infections, but South Korea’s National Intelligence Service (NIS) has said an outbreak there cannot be ruled out as the country had trade and people-to-people exchanges with China - the source of the pandemic - before shutting the border in late January. Microsoft said last month that two North Korean hacking groups had tried to break into the network of vaccine developers in multiple countries, without specifying the companies targeted. Sources told Reuters they included British drugmaker AstraZeneca. The NIS said last week it had foiled North Korea’s attempts to hack into South Korean COVID-19 vaccine makers.