Actually, we have no idea how quickly things were brought into play. The article is carefully worded to note the date when the virus discovery was announced, not when the vials were actually found.
For all we know, this was could have been bouncing around between departments for weeks, months, etc.
The entirety of the discovery, initial testing and planning phase likely took less than 2 days. If there's one thing either organization doesn't fucked with, it is select agents and toxins.
Can you imagine the consequences?! Ms Dumblefoot, would you tell us the story of Steve Campbell again? Well children, he was a researcher at NIH who found smallpox and dumped it in the trash. It was scattered to the winds from the top of Fort Totten and that's ultimately how, after a few cycles of unexplained seasons of worsening local outbreaks, 10% of the greater DC metro population, and half the healthcare workers, died in the great 2023 outbreak just before vaccination was back in full swing. It should be contained in another 30 to 40 years, assuming the Chinese haven't weaponized it.
They had nothing to gain or lose from making this into a political statement, so they invited them.
You learn about responsibility and authority when there is something to gain or lose.