Council News Vol. 7, no. 2

3 I

USHERING IN AN ERA: EDIBLE VACCINES
An edible vaccine triggers good immune responses
against Escherich'a coli, reported collaborating
scientists from the University of Maryland, Boyce
Thompson Institute for Plant Research, and Tulane
University-all supported by NIAID.

Clements, Ph.D., and colleagues
at Tulane University School of
Medicine showed that transgenic
potatoes with the same toxin
segment stimulated strong immune responses in animals.
The transgenic potatoes were

Edible vaccines open an exciting
new potential to prevent global
scourges such as hepatitis and
diarrhea.
Vaccine-housing crops can be
grown locally, circumventing
problems of storage and administration that plague the use of
traditional vaccines in the less
developed world.
In addition to pathogenic E. coli,
a major cause of diarrhea worldwide, scientists are already exploring the technique for other
antigens.
Edible vaccines are in early
development for other intestinal
pathogens: potatoes and bananas
for Norwalk virus, potatoes and
tomatoes for hepatitis B.
The phase I E. coli trial began
last fall at the University of

Maryland School of Medicine's
Center for Vaccine Development under the direction of
Carol Tacket, M.D.
Volunteers ate bite-sized pieces
of raw potato genetically engineered to produce part of an E.
coli toxin.
Just before being eaten, the
potatoes were peeled and cut
into 50-gram and 100-gram
doses. Each participant received
three doses of either 50 grams or
100 grams of potato over a
three-week period.
Ten of the 11 volunteers had
fourfold rises in serum antibodies, and six had fourfold rises in
intestinal antibodies. No serious
adverse side effects were reported. Earlier in vitro and preclinical studies by John

created
and grown
by Charles
Arntzen,
Ph.D.,
Hugh S.,
Mason,
Ph.D., and
colleagues
at the
Boyce
Thompson
Institute
for Plant
Research,
an affiliate
of Cornell
University.
The study
was re
Edible
vaccines are
in early
development
for intestinal
pathogens:
potatoes and
bananas for
Norwalk virus,
potatoes and
tomatoes for
hepatitis B

ported in May Nature Medicine
(vaccine supplement), 1998;4(5):
502-03 Haq TA, Mason HS,
Clements JD, and Arntzen CJ.

NIAID COSPONSORS VACCINE SYMPOSIUMMEDICINE FOR THE 21ST CENTURY
NIH is looking to partner with industry to spur
research of new vaccines.

On June 15, NIAID cosponsored a symposium at BIO 98 to
bridge interest in vaccine development with the biotech community and industry. Called
Vaccines: Visions for the Future,
the symposium ventured into

the waters of vaccine high technology, some of which are
flowing into such mundane
channels as bananas and milk.
Companies are well into the
development of new vaccine

technologies including edible,
DNA, and aerosol vaccines;
transgenic milk; genomics; and
plant factories as well as vaccines for an expanded list of
difficult organisms, including
TB, meningococcus, rotavirus,
and malaria.
First of the new-generation
vaccines is a live-attenuated,
cold-adapted, trivalent influenza
nasal spray vaccine for flu.
Vaccine Meeting--continued on
page 19