The intermediate hosts for Taenia saginata and T. solium are cattle an
d pigs (and humans for the latter), respectively. In vitro-hatched (bu
t not activated) oncospheres of both Asian Taenia (T. saginata asiatic
a, a new subspecies of T. saginata or T. asiatica, a new species) and
T. solium injected subcutaneously into the backs of mice with severe c
ombined immunodeficiency (scid) developed into fully matured cysticerc
i. Five-month-old metacestodes of Asian Taenia had no hooklets and wer
e bigger in size than those previously reported and similar to those o
f T. saginata. Their morphology suggested that the cysticerci were mor
e advanced than those in the intermediate host animals. It is suggeste
d that scid mice are valuable experimental animal models for studying
human taeniid cestode infections.