The suggestion that the Wuhan Institute was the source of SARS-CoV2 has raised its head again. The Biden administration is taking it as seriously as Trump did, possibly for the same political reasons. Unless the CIA can obtain biological samples from the earliest cases in China, one cannot see the Biden investigation making any more progress than the official WHO survey did.
People should look at the evidence from the other way: not that the virus turned up in the Wuhan market because of the proximity of the institute, but that the virus had leapt the species gap elsewhere in China some time before and that it was only identified in Wuhan because there were experts on hand in the city. I understand that there are rural parts of China where people live very close to bats of the kind which bear the coronavirus, even sharing huts with them.
The PR line that the virus entered the country is generally regarded as ludicrous outside China. One wonders why their government persists in that, allowing the allegations against the Wuhan institute to thrive. Probably they would rather have scientific workers (whom bureaucrats and politicians dislike) take the blame than admit that the virus had been free in the wild for months without the government taking any action.
The top brains at the Wuhan institute may well have come to this conclusion based on sequencing the samples in their possession. That would be one reason for the restricted access granted to the WHO scientists by the Chinese authorities. Until the Wuhan research findings are published, or an independent lab has access to the Chinese samples, we shall not know for sure. In the mean time, if it has not been done already, those which have been retained in Italy should be checked. It always seemed unlikely that the large number of cases there resulted from a couple of tourists from Wuhan in December 2019. There are also likely to have been other coronavirus deaths in France and Italy which were put down at the time to pneumonia or influenza based purely on symptoms. (I refer to earlier postings on Covid-19 especially https://ffrancsais.blogspot.com/2020/06/covid-19-hidden-history.html.)