Wuhan, China — More than a year after the world’s first known coronavirus cases appeared here, a World Health Organization team of experts finally landed in Wuhan on Thursday to try to trace the origin of the deadly virus. But the highly-anticipated visit is now being met with international skepticism because of how long the Chinese government waited to give access to the WHO. The bottom line, scientists say, is that a definitive explanation of COVID’s jump from wild animal to humans may be months, if not years, away. With SARS in 2003, it took scientists at least four years to conclude that coronavirus jumped into the human population from bats in China’s southwest Yunnan province. China fights COVID-19 flare-up in city of 11 million With the new coronavirus, there’s no guarantee the world will ever know. But that’s the mission for the WHO now in Wuhan. The team flew in via Singapore, with 13 experts from 10 countries, including the U.S., United Kingdom, Russia and Vietnam. CBS News was waiting at Wuhan’s Tianhe airport when they arrived, but the scientists were kept quarantined from the public the entire time — escorted by PPE-wearing Chinese officials down an elevator, through a bubble-barrier corridor then outside onto a bus that took them to their quarantine accommodation. They will remain there for at least the next two weeks – par for the course for anyone traveling into China from abroad under current anti-virus measures. Speaking to reporters in Beijing on Thursday, Chinese Foreign Ministry spokesman Zhao Lijian said China would “support and offer convenience for the WHO experts’ joint international investigation” in the country, adding that even during their quarantine, “Chinese scientists and medical experts will engage in deep communications” with the team via video conferencing. The WHO said Thursday that the team would start its work immediately to determine how Wuhan became the world’s first COVID-19 epicenter. That’s expected to include interviews with people at area hospitals, and from the Southwest China Wholesale Seafood Market, which, at one point was believed to be ground-zero for the virus’ jump from animals into humans. CBS News was at the shuttered market one year ago, almost to the day, as security forces kept journalists at bay and workers in hazmat suits cleaned and disinfected the sprawling site. (See our January 20, 2020 report below.) Last week, explaining the delay in admitting the WHO team, China’s Foreign Ministry called tracing the origin of the disease “incredibly complicated,” and said that, “to ensure the work of the international expert team in China goes smoothly,” it needed to complete unspecified “procedures and make relevant arrangements.” China’s government has been on a mission to shift blame for the pandemic to other countries, and scientists say they cannot rule out the possibility that it emerged elsewhere. But the bar is high for the world to believe anything other than COVID-19 came out of China. For its own citizens, the official Chinese narrative is that the Communist Party beat the coronavirus, and the government often points to the fact that the virus is still raging in many other places around the world.