In the very specific case of Covid-19, what should have happened to prevent the virus from spreading in the first place?
This is directly tied to the issue of commercial wildlife trade and wildlife consumption.
WCS recommends stopping all commercial trade in wildlife for human consumption (particularly of birds and mammals) and closing all such markets. Rigorous enforcement of existing laws, regulations, and international treaties that deal with wildlife trade and markets is critical and necessary, but this is simply not enough. A new paradigm is needed if we are to avoid a pandemic such as the one we are experiencing today.
Beyond that, you need to monitor better. You need to know what viruses are out there and you need to clean up your supply chains the best we can.
The issue is, right now as we speak, there are many other coronaviruses out there in wildlife being consumed by humans – and any one of them could jump. So we might have a Covid-21 or Covid-22 coming our way and we need to strengthen the surveillance systems, reduce deforestation and stop all commercial trade in wildlife for human consumption (particularly of birds and mammals).