Please read the article. The US massively funded gain-of-function research on viruses including on coronaviruses. This research was eventually banned in the US and so they moved it off-shore to evade those regulations. China should certainly have come down a lot harder on any US-backed biowarfare research in the country.
Prigozhin exploded on his way out of Moscow. To me it really feels like Putin did everything possible to avoid killing his friend and only did the final hit once it was clear that Prigozhin hadn’t learned his lesson and would continue to not follow orders.