With 10 million known cases of infection and half a million deaths, the Covid-19 pandemic has outrun the world’s epidemiologists . Six months after China confirmed the existence of the new coronavirus, they are none the wiser about the how, where and when of its origin – key to fighting it more effectively. The urgent importance of this knowledge remains paramount, since World Health Organisation chief Tedros Adhanom Ghebreyesus says the worst is yet to come . An imminent WHO investigative mission to China could mark a turning point in the search for answers. Sadly the search has been hampered by the same issues that helped accelerate the spread of the virus , identified by the WHO chief as the lack of national unity and global solidarity, and a divided world. The lack of national unity is typified by conflicted responses in the United States, which has the highest virus toll. The lack of solidarity is found in politicalisation of the investigation, with some in the US calling it a “China virus” and an angry China countering that the US military might be responsible for bringing it into Wuhan. The issue marred the World Health Assembly in May, as the US pushed for an inquiry into China’s handling of the outbreak and sharing of information. It is therefore positive news that the six-month milestone is to be marked by the dispatch of a WHO team to China, similar to a joint WHO-China international scientific mission in mid-February. “We can fight the virus better when we know everything about how it started,” Tedros said. The suspected link to a Wuhan wet market has been blurred by the lack of clear evidence, and by a number of early infections with no clear connection to the premises. At this late stage experts are sceptical about the prospects of the WHO inquiry unearthing new insights. Science still has to reckon with politics. Yanzhong Huang, a global health expert with a non-profit think tank in New York, says the level of access granted to the WHO team may depend on who is in it and whether Beijing perceives it as neutral. On the other hand China will not want to be seen as uncooperative. It does not sound as if a breakthrough is just around the corner. But it is the best shot the world has of a multilateral approach to a lethal scourge that knows no boundaries and remains largely a mystery.