Most farmers sow fields of alfalfa and reap acres of salad
greens. Mitch Hein is cultivating alfalfa sprouts that could stem a
In a locked vault behind a chain-link fence in a corner of an
underground parking garage, Hein is tending a garden of unusually
potent health food.
Hein is a cell biologist at the Scripps Research Institute.
Each green plastic pot in his growth chamber contains a scraggly
alfalfa seedling that he has genetically engineered to contain just
enough of the deadly cholera toxin he thinks will confer immunity
on anyone who eats enough of it.
Each plant is an edible vaccine: No need for purified,
refrigerated serum or hypodermic needles. Just salad dressing.
While scientists at large biotechnology companies labor to
improve supermarket tomatoes or create crops resistant to chemical
sprays, a handful of researchers like Hein are transforming
ordinary fruits and vegetables into unconventional medical vaccines
that promise to revolutionize public health.
If these genetic gardeners are successful - and human clinical
trials bear out their preliminary laboratory findings - an apple
one day actually may keep the doctor away. Vaccinations against
common diseases that kill tens of millions of people every year
could involve no more than a slice of bread or a piece of
The researchers want to eradicate deadly diseases by simply
giving people in developing countries the genetically engineered
seeds that will sprout edible vaccines. They hope to reach the
point where people who have no medical training, in villages far
from hospitals or public health stations, would find tending to
their health as easy as tilling a garden.
That day is years away, but scientists are making significant
strides toward demonstrating that such plants are feasible. Last
month, Hein harvested his first crop of the alfalfa vaccine from a
small field in Ardmore, Okla. Now, 15 crates of sprouts are drying
in a corner of his Southern California lab.
Biologists like Hein are seeking ways to link agriculture and
human medicine. They have coupled advanced theories of how the
body's immune system fights off disease with the latest in
recombinant DNA technology.
They are trying to take advantage of the natural ability to
build resistance against an illness through exposure to edible
nontoxic compounds called antigens, isolated from a virulent virus
or bacteria. The antigens provoke the antibodies that confer
immunity without actually making you sick.
Charles Arntzen at Texas A&M University is trying to develop a
banana that can prevent hepatitis B, an illness that strikes up to
300 million people worldwide.
Arntzen, a molecular biologist, already has produced a potato
that prevents gastroenteritis. …