Vegetarians would take it, as it does not come from a live breathing animals. Vegans, on the other hand would refuse it because we object to human use of animals, and all meds have been tested on animals. And die-hard vegans would rather lose their life than go against their beliefs.
Actually it would depend on the vegan. I would take it if I needed it. (After all, I'm not much good to the animals dead.) Until FDA rules change, if a vegan were going to refuse all meds tested on animals, there's no need to come to the hospital, they can just die at home instead.
In response to the thought that vegans wouldn't use E.coli based things, b/c it comes from an animal...Bacteria are not in the animal kingdom,they are in thier own, just like plants are in thier own, so why would it matter? And they aren't aerobic like most animals are, they are facultative anaerobes. When do vegans stop considering something an animal?
The most common place for vegans to draw the line is sentience. If they can feel pain, vegans won't eat it. So for insulin, it's not the coming from e. coli, it's the tested on animals that's the problem for most vegans.
I personally just try to do the least harm possible. I've seen a lot of vegetarians that are sticklers for following all the "rules" and then after 6 months, 2 years, a decade decide that it's just "too hard" and give it all up. I'd rather relax a little bit (I'm not going to beat myself up over the fact that I found out a restaraunt I used to frequent had been adding chicken broth to what I thought was vegan-friendly rice, I'll just stop eating it) and make it a lifetime. I'll also use meds that were tested on animals because frankly, they all were under current FDA regulations. I try to go as cruelty free as possible. I use synthetic/plant derived estrogen replacement therapy rather than Premarin because horse cruelty is unneccesary in getting me my estrogen. If I were a burn patient, don't come near me with porcine grafts, because that would freak me out.
I draw the line where I can live with myself. I've had plenty of omnivores come up to me with their reasons why I'm not "vegan enough." Well, I'm causing less cruelty to the animal world than they are, and as the world becomes more animal friendly, it will be easier to find even more animal-friendly items.
Also remember, some self-proclaimed vegans will eat fish and wear leather. One of the reasons I said earlier in the thread that patients need to define their limits, is that everyone is different where they draw their line with how they live their "label," and this is a prime example.
If you're interested in livable vegan ethics, Joanne Stepaniak is a great resource:
http://www.vegsource.com/jo/index.htm