A World Health Organization team in China to investigate the origins of the Covid-19 pandemic ended 14 days of hotel quarantine on Thursday, kicking off the field portion of their month-long mission. Team members were seen boarding a bus outside their hotel in Wuhan around 3pm, after being cleared to leave following the mandatory isolation period. The 14-member team includes international veterinary, virology and medical experts, as well as five WHO officials. They have spent the first two weeks of their mission in video meetings with Chinese scientists, as they work to understand where the coronavirus that causes Covid-19 came from and how it began spreading in Wuhan, where it was first identified in late 2019. Several of the international experts took to Twitter on Thursday to celebrate the end of the isolation period. “Graduation!!!” virologist Marion Koopmans of the Erasmus University Medical Centre in the Netherlands tweeted, above a picture of her holding an official medical form noting the end of the quarantine. “Congratulations!” the team leader, WHO animal disease expert Peter Ben Embarek, wrote in reply. Another member, disease ecologist Peter Daszak, president of the US-based EcoHealth Alliance, posted several photos from his hotel room, with a yoga mat and weights visible in one area and his laptop alongside a stack of documents on the other. “Slightly sad to say goodbye to my ‘gym’ & my ‘office’ where I’ve been holed up for last 2 wks!! (Clue – It’s all in the same room … ) Moving into next phase of work now w/ @WHO mission team & China counterparts,” he wrote. “Surprisingly easy to do 14 days in quarantine, the high workload meant days have sailed by & this is a v nice hotel,” Daszak said. Covid-19 scientists seek the invisible in Wuhan investigation into deadly pathogen The WHO has yet to release details of the team’s itinerary, but they are expected to make site visits and conduct interviews with early patients. In particular, the team is seeking to understand how the earliest patients may have been infected and looking at past research around a local seafood market linked to a number of the first known cases, the WHO has said. Members of the WHO team have provided little public comment about the nature of their meetings with the Chinese counterparts, although Daszak said they were reviewing data that had not previously been publicly released, US media outlet NBC News reported earlier this week. The mission, some six months in the making, got off to a false start earlier in January after team members already en route were turned back because they were not cleared for landing in Beijing, prompting WHO chief Tedros Adhanom Ghebreyesus to express his disappointment with the situation . Later, two members were held back in Singapore, while the rest of the team departed for China, because they did not pass a required antibody test . One was later cleared to continue on to Wuhan , though should still be in the quarantine period. Team members have shared a bit of what life has been like over the past two weeks in quarantine via Twitter, which is blocked in China but can be accessed using a virtual private network, or VPN. Vietnamese animal health expert Hung Nguyen of the International Livestock Research Institute last week said he was trying to stay active after a long day of meetings, posting a photo showing he had run over 5km (3.1 miles) in his room. “Quite fun but patience needed to do it in a quarantine room!” he wrote above a selfie showing his 7.22 km/hour pace. Observers around the world are eagerly watching the team’s progress during the mission, especially as questions have been raised about the level of access to data the team may have, and as Beijing has repeatedly said that the virus may not have come from the country. The WHO has warned that finding the origins of a novel virus can take years, and that investigators need to be open to follow data wherever it leads.