Yes, I still test my code.
But when I write it, I do it with the lessons I’ve learned over decades, and it’s usually close to working before the first test comes into the picture.
That’s where we are with vaccine production: we’ve been cranking them out for decades, and the process is so robust that failures at in the six plus nines range of outliers.
https://www.researchgate.net/figure/Drug-discovery-and-devel...
You’re building things from a library of tested techniques.
Vaccines aren’t drugs.
They’re a method of delivering material to the immune system for it to do its thing.
We do that by finding the thing we want to present, finding a pipeline to extract that, and finding a delivery mechanism that is tested and compatible.
We don’t “discover” a new flu vaccine ever my season, we put together this seasons release.
That’s why it didn’t take years to design and release a new vaccine for covid: we have the technology already, we just needed to pick the payload and select the rocket best suited for the job.