Then, as the evidence continued to mount, it suddenly became acceptable to talk about it in "respectable" circles. Today, however, we appear to have gone full-circle: a determined effort is once again underway to dismiss the lab-leak theory for good — even though no new evidence has emerged to disprove it.

Considering the endless ways in which the pandemic and our response to it have changed the lives of every human being on the planet, it's astonishing to consider how little is actually known about the origins of the virus. Two and half years on, we are still very much in the dark as to when, how and even where SARS-CoV-2 first made its appearance.

This isn't because our efforts to get to the bottom of the mystery have proved fruitless, but rather because those efforts have been systematically thwarted by the world's two most powerful governments: America and China. This is the mother of all Covid conspiracy theories — but it's also true.

One of the main "conspiracy theorists" is none other than Jeffrey Sachs, director of the Center for Sustainable Development at Columbia University, president of the UN Sustainable Development Solutions Network and chair of the Lancet Covid-19 Commission. He is not your typical tinfoil-hat-wearing internet crank. Sachs recently co-authored a paper in the Proceedings of the National Academy of Sciences calling for an independent inquiry into the virus's origins. He believes there is clear proof that the National Institutes of Health (NIH), the primary US public health agency, and many members of the scientific community have been impeding a serious investigation into the origins of Covid-19 in order to cover up evidence that US-funded research in Wuhan may have played a role in the creation of the SARS-CoV-2 virus.