Standard operating procedure at the FDA is to prohibit everything until it has undergone comprehensive testing. Since this virus didn't exist until recently, neither did the test, so even once the test existed it was illegal to use it and the words swift and efficient are not appropriate to describe the process for changing that.

People have been pointing out for years that the FDA's approach is excessively conservative, but the typical response is that they're doing it to save lives, even though there is a point past which being too conservative actually costs lives by keeping life-saving things off the market. This was a prominent example of that actually happening.