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Human sperm make the perfect vehicle for ferrying vaccines, gene therapy
drugs and contraceptives to the heart of target cells in the body, claims
Virginia Scofield of the University of Southern California in Los Angeles. In
her patent (US 5 804 191), Scofield says that sperm are incubated for 12 hours
in a salt solution. The drugs or vaccines are added, and bind to the surface of
the sperm. Irradiation, freezing or adding formaldehyde will deactivate the
sperm to avoid causing pregnancy. Then an injection or suppository can deliver
the crippled sperm to the mucus membranes in the part of the body you are trying
to treat.