This old novel is as fresh as it always was. It's high-concept hard science fiction, hard enough to scratch diamonds unless you dismiss the biosciences as magic. The idea of healing with bioengineered snakes that produce designer drugs on order - in a culture that may not be able to produce hypodermic needles in mass quantities for lack of resources and factories - is startling and logical at the same time.
It's partly an old-fashioned post-toastie, but the after-WWIII setting is background, not the main point. However, the postwar world is a world with no easy answers. Everything is a tradeoff. The process that immunizes healers against snake venom also leaves them with hyperactive immune systems, hence sterile and very vulnerable to auto-immune diseases. A hard and isolated life leads to ignorance and fear; an easy affluent life, to easy contempt for the maimed and wounded. The low-hanging fruit was all picked before the war, and resources are scarce indeed. Scavenging is an accepted and sometimes profitable occupation, and there is a great, if unspoken, concern with keeping the birth rate down. And the greatest virtue is simply to keep on keeping on.
And yet it's a hopeful book. The characters are likeable, by and large. There seems to be a cooperative spirit among the people of this post-cataclysmic world, or at least certain shared cultural dictates which everybody but the bad guys and the people of the locked and fortified underhill City accept. Snake in particular is a memorable character.
Highly recommended as a reread.