Immunization, that brilliant medical invention, is a way of arming the body's defences in advance of an attack. You inject a foreign protein characteristic of the disease organism; the immune system raises antibodies against it, and acquires expertise in detecting the protein and neutralizing its threat. Any pathogen bearing that protein is thereafter rapidly overwhelmed by primed and practised immunological defences.

Daedalus now wants to generalize this technique. The immune system seems to be able to produce antibodies to any protein, or any number of proteins. So DREADCO biologists are devising a universal immunization. At first they planned to exploit modern combinatorial chemistry to synthesize a mixture of all possible proteins, and inject it into test subjects. But the combinatorics defeated them. With 20 possible amino acids at each link in a protein chain, an immunization containing just one molecule of all possible 20-link chains would weigh well over a kilogram. And much longer chains are common.

However, life uses only a small subset of proteins, those with useful foldings; many of them are common to several species. So Daedalus's team is now scouring farms, zoos, botanical gardens, and culture archives to acquire samples from, or a specimen of, every known living thing. They plan to mix and homogenize the specimens, and extract their proteins. The resulting mixture will still be wildly complicated, but should be a feasible immunization.

DREADCO's ‘Noah's Ark Vaccine’ will be powerful indeed. An injection of it will bring a horrific feverish reaction as the subject's immune system is challenged simultaneously by millions of foreign proteins. A graded series of shots will be needed, starting with very tiny doses and only gradually building up to the full prophylactic dose. The subject will then be immune to absolutely everything.

Given to the whole population, Noah's Ark Vaccine will transform medicine. Colds, ‘flu, infections, all the bacterial and viral diseases will vanish. Even if the baffled organisms mutate, they will simply hit another component of our fully primed immune systems. Even a pathogen protein not in the vaccine may still be close enough to one that is, to trigger its response. Medical costs will be cut right back. Only diseases of the immune system itself, such as AIDS, will remain to plague us.