This review states the technologies, host plants, current status, recent patents, the future of this new preventive modality, and dif-ferent regulatory issues concerning edible vaccines.
Trang 1Send Orders for Reprints to reprints@benthamscience.net Recent Patents on Biotechnology, XXXX, XX, 000-000 1 REVIEW ARTICLE
1872-2083/XX $65.00+.00 © XXXX Bentham Science Publishers
Edible Vaccines: A Patent-Driven Exploration of Immunization Technologies
Sahil Kashyap1, Shikha Kamboj1, Rohit Kamboj1, Kumar Guarve1 and Sweta Kamboj1,*
1 Guru Gobind Singh College of Pharmacy, Yamuna Nagar, Haryana
Abstract: Vaccines are biological preparations that improve immunity to particular
dis-eases Particularly for poor developing nations, edible vaccines show significant potential
as a financially advantageous, simple to administer, straightforward to store, fail-safe, and socially and culturally acceptable vaccine delivery system A vaccine incorporates the gene-encoding bacterial or viral disease-causing agent in plants without losing its immunogenic property Potatoes, tomatoes, rice, soybeans, and bananas are the primary plants for edible vaccines It activates the systemic and mucosal immunity responses against a foreign disease-causing organism It offers exciting possibilities to reduce dis-eases like hepatitis B, rabies, HIV/AIDS (human immunodeficiency virus infection and
acquired immune deficiency syndrome), etc These vaccines provide many benefits, like
being convenient to administer, efficiently storing, and readily acceptable drug delivery systems for patients of different age groups So, an edible vaccine may be the most con-venient vaccine to improve immunity However, there are a lot of technical and
regulato-ry challenges to overcome in the way of edible vaccine technology Though all seem surmountable, various technical obstacles and regulatory and non-scientific challenges need to be overcome Moreover, edible vaccine patents represent a cutting-edge area of biotechnology, where the integration of genetic material into edible substances holds great promise for revolutionizing vaccination methods These patents aim to harness the potential of plants and other edibles to stimulate immune responses, offering a potential alternative to traditional injectable vaccines This review states the technologies, host plants, current status, recent patents, the future of this new preventive modality, and dif-ferent regulatory issues concerning edible vaccines
A R T I C L E H I S T O R Y
Received: July 31, 2023
Revised: November 15, 2023
Accepted: November 20, 2023
DOI:
10.2174/0118722083275041231219060829
Keywords: Edible vaccine, Mechanism of action of edible vaccine, Transgenic plant, Biotechnology
1 INTRODUCTION
As man has progressed in his development, he
has abused this environment so much in his
strug-gle for survival that microorganism infection is
rising In this way, to be safe from illness, a person
needs to have good health [1] The higher our
im-munity, the better we can keep these diseases away
and protect ourselves from these dreaded
infec-tions Therefore, we will be protected from the
vi-rus only when our immunity is good, so first of all,
*Address correspondence to this author at the Guru Gobind
Singh College of Pharmacy, Yamuna Nagar, Haryana;
E-mail: swetakamboj20@gmail.com
we have to increase our immunity, and for this, we should take vaccines to protect against different infections so that our bodies can get ready for the coming dangerous virus infection by building up the immunity beforehand [2] A vaccine is a bio-logical preparation that stimulates our immune system to generate more antibodies toward a par-ticular disease-causing antigen The vaccine con-tains a specific disease-causing virus antigen's killed or attenuated (inactive) form When these inert antigens enter our bodies, our immune sys-tem recognizes them as harmful foreign bodies and starts the production of antibodies against that par-ticular antigen [3] These antibodies are stored in
Trang 2our body, and when the disease-causing virus
en-ters our body, our immune system releases the
an-tibodies to neutralize the disease-causing antigen
and normalize the body [4] In 1796, Edward
Jen-ner proposed the first vaccination against
small-pox But since then, needles have been used for the
vaccine, so the immunization process has become
painful and complicated, and it is not possible to
take the vaccine without an experienced doctor
[5,6] The storage of vaccines is also a difficult
task under proper conditions Also, reusing
nee-dles can transmit serious infections like Hepatitis
B, HIV/AIDS (human immunodeficiency virus
infection and acquired immune deficiency
syn-drome), syphilis, etc
WHO (World Health Organization) estimates
that 10 million children die in developing
coun-tries yearly from infectious diseases that vaccines
could prevent However, conventional vaccines are
expensive and inconvenient for the poor people of
developing nations [7,8] In such a situation,
find-ing a few new cheap vaccination methods that
people can take conveniently without any pain or
the help of a professional becomes even more
es-sential That's why food or oral vaccines are the
only medium by which we can increase our
im-munity by taking them ourselves without
profes-sional help [9] The American biologist Dr Charles
Arntzen was the first scientist to introduce us to
the concept of an edible vaccine [10, 11] These
are the subunit vaccine types prepared by a plant's
genetic modification [12] Various transgenic
techniques incorporate The virus antigen into a
suitable host plant to produce edible vaccines [2]
The person himself eats these oral vaccines
with-out any professional help to improve or boost his
immunity against a particular virus infection
Alt-hough the orally administered food vaccines
di-rectly go to the gastrointestinal tract, they now
strengthen the mucosal layer of the GIT and make
a protective shield against the virus antigen [13]
1.1 Genetically Modified Plants
Transgenic plants are genetically modified
plants created through DNA recombinant
tech-niques It is a modified plant in which different
genes are combined by genetic engineering
tech-niques to form a new species or plant Plant
genet-ic engineering has long been used for various
pur-poses, including improving fruit quality,
increas-ing yield, and producincreas-ing pest-resistant plants [14]
For example, Bacillus thuringiensis corn is a
transgenic corn that contains a toxic protein against insects and pests but is entirely safe for humans Therefore, genetic modification offers a wide range of benefits [15] Thus, genetic engi-neering makes edible vaccine preparation possible, stimulating our immune response without harming
us conveniently However, different types of plants have different abilities because their nutri-tion varies As a result, selecting a host plant is an
essential factor in producing edible vaccines via
genetic engineering The host plant is the plant that
is best suited for the production of edible vaccines [9] It is a challenging task to choose the best host plant Several factors may affect the host plant
se-lection, which are shown in Fig (1)
1.2 Plants Commonly Used as Host
The host plant is the plant that is best suited for the production of edible vaccines It is a challeng-ing task to choose the best host plant Several fac-tors may affect the host plant selection, such as antigen stability with plant genes, the degradation time of fruit, the effect of physical characteristics
on antigen stability with plants, etc [16,17,18]
Various types of plants are used for edible vaccine production or clinical trials Generally, tobacco, potato, tomato, maze, rice, and carrots are used for the production of edible vaccines due to their vari-ous characteristics, which are explained as follows [4, 5, 16, 19-22] Now, let us look at some of the specific plants commonly used for the production
of edible vaccines and the characteristics that make them suitable:
1.2.1 Tobacco
Tobacco is often used for producing edible vac-cines due to its relatively simple genetic makeup and well-established transformation techniques It has been used in research for many years and is particularly suitable for antigens that can be pro-duced in the leaves
1.2.2 Potato
Potatoes are a preferred choice because they store well, have a relatively long shelf life, and their tubers can be used as an edible vaccine deliv-ery system They are also genetically accessible and can be engineered to express vaccine antigens effectively
Trang 3Edible Vaccines Recent Patents on Biotechnology, XXXX, Vol XX, No XX 3
1.2.3 Tomato
Tomatoes are another popular choice as they
are widely consumed, and the fruit can be used as
a delivery system Their fruit structure is relatively
durable, making them suitable for vaccine
stabil-ity
1.2.4 Maize (corn)
Maize is used for producing edible vaccines,
primarily for antigens that can be expressed in the
corn kernels It is a staple crop in many regions,
making it an accessible choice for vaccination
ef-forts
1.2.5 Rice
Rice is consumed globally and is used for
vac-cine production, particularly when targeting
dis-eases prevalent in regions where rice is a dietary
staple The seeds of rice plants are utilized to
ex-press antigens
1.2.6 Carrots
Carrots are a choice for antigens that can be
ex-pressed in the root, which is edible and has a
rela-tively long shelf life They are especially useful for
vaccines targeting diseases that can be combated
via the mucosal immune system Researchers
care-fully evaluate these factors to select the most suit-able plant for their edible vaccine production, with the goal of creating an effective and accessible
means of immunization Table 1 shows the list of
plants that are used as hosts for edible vaccines
1.3 Mechanism of Action for Edible Vaccine
As we know, the mucosal lining of the Gastro-intestinal Tract (GIT) is the primary site for the risk of viral infection Most of the pathogens, bac-teria, and viruses enter the oral region That is why the mechanism of action of the edible vaccine stimulates both the systemic and mucosal systems
of our body [10, 16] First, this mucosal-targeted vaccine enters our body through the oral region, which is edible and reaches our gastrointestinal area, and the outer cell wall of the plant protects the antigen from enzymatic degradation [12] When this edible antigen reaches our intestinal re-gion, the digestive enzymes or the intestinal bacte-ria break down the outer capsule of the antigen (plant cells) and releases the antigen near the
Pey-er patches, which consist of 30-40 lymphoid nod-ule which contains the follicle from which the germinal centre develops, and these follicles helps for the penetration of the antigen toward the epi-thelium lining of the intestine Then, it is taken up
Fig (1) Factors affecting the host plant selection (A higher resolution / colour version of this figure is available in the
elec-tronic copy of the article)
Trang 4by the microfold cells (M cells) These antigens
containing M cells activate the B-cells, which
causes B-cells to leave lymphoid follicles and
reach the mucosal-associated lymphoid tissue
(MALT) It causes the degradation of plasma cells,
and thus, Ig-A antibody production occurs These
antibodies are then transported and stored in the
lumen When the virus antigen enters our body,
these antibodies get released from the lumen and
neutralize the antigen [23-27] Fig (2) represents
the mechanism of action for edible vaccines
2 EDIBLE VS TRADITIONAL VACCINES
One of the most significant benefits is the
con-venience they provide Administered orally, these
vaccines eliminate the need for injections, making
them easier to distribute and use, especially in
are-as with limited access to healthcare facilities
Moreover, the safety profile of edible vaccines is considered superior, as they eliminate the risk of contamination with harmful substances or patho-gens during production and administration In ad-dition to convenience and safety, edible vaccines offer remarkable cost-effectiveness By using plants as bioreactors, they can be produced at a fraction of the cost of traditional vaccines, making immunization more accessible and affordable for a broader population This cost advantage is crucial
in low-income regions where traditional vaccines might be financially burdensome Edible vaccines hold immense promise in transforming vaccination strategies globally Their convenience, safety, in-creased acceptance, versatility, and stability make them an appealing alternative to traditional vac-cines, potentially revolutionizing immunization efforts and improving healthcare access for all [28, 29], as we discussed the various advantages and
Table 1 List of plants used as Host for edible vaccine
Sr.no Host
i Tobacco Charles Arntzen Abundant material for protein
characterization
It may produce a toxic Effect
Hepatitis B Virus (HBV) Norwalk virus
Hepatitis B Gastroentiritis
ii Potato
Charles Arntzen and Mason William Langridge
Readily available and cost-efficient
Tuber-specific promoter available
The cooking process may break 50% of vaccine protein
Unpalatable in raw form
Norwalk Virus Hepatitis B virus Cholera
Diarrhoea Abdominal pain Hepatitis B Cholera
iii Tomato Chowdhury and
Bagasara
Palatable food Eaten raw
Not grow well in regions where vac-cines are needed
Quickly spoil Acidic fruit may be unstable with some antigens
Plasmodium falciparum Rabies virus
Malaria Rabies
iv Banana Charles Arntzen
Easily Consume in pure form
No need to cook Grow well in tropical areas
Available in all seasons
A more considerable period is required for cultivation
High cultivation space requirement Very expensive in the greenhouse Transgenic trees require approx 12 months to bear fruit
Hepatitis B Virus (HBV) Hepatitis B
v Maize Octavio
Guerrero-Andrade
Cheaper crop Readily available in develop-ing nations
Not eaten raw Cooking may dena-ture the antigen
Newcastle disease virus (NDV)
Newcastle dis-ease
Trang 5Edible Vaccines Recent Patents on Biotechnology, XXXX, Vol XX, No XX 5
disadvantages of edible vaccines However, a
de-tailed comparison between the edible vaccine and
the traditional vaccine is important to know how
the edible vaccine is comparatively better than the
conventional/traditional vaccines or how it is
ben-eficial from the physical and economic point of
view [29] Table 2
3 METHOD OF PREPARATION OF EDIBLE
VACCINES:
There are various types of methods are used for
the preparation of edible vaccine, which are as
fol-lows:
3.1 Plasmid /Vector Carrier System
As per Fig (3) (Plasmid /vector carrier system),
it is a simple and widely used method for
produc-ing edible vaccines through transgenic plants A
tumefaciens is a naturally occurring soil bacterium
used to transfer small DNA segments into the
plant genome by the process of transformation
We sterilized a small section of the plant in this
process They suspended the fixed part of the plant
into bacteria carrying antigen culture, allowing the
bacteria to deliver the antigen genes into the plant
cells Then, expose the plant cells to an antibiotic solution to kill the cells lacking new genes and al-low the callus to form After some time, the callus sprouted, shoots, and roots After that, the whole plant is generated from individual plant cells The existing studies showed that genes are successfully expressed in experimental plants When it is given orally to animals, the transgenic plant extract con-taining antigen induces the production of serum antibodies in that animal [20, 21, 30-34] The method is explained below:
v Plasmid Selection and Modification The plasmid is then modified by inserting the DNA of interest into the plasmid's DNA back-bone This DNA of interest can be a gene that needs to be expressed, a therapeutic gene for gene therapy, or an antigen for vaccine devel-opment
v Transformation or Transfection The modified plasmid is introduced into the host cells This can be done through tech-niques like transformation (for bacteria) or transfection (for eukaryotic cells, such as hu-man cells)
Fig (2) Mechanism of action for edible vaccine (A higher resolution / colour version of this figure is available in the
elec-tronic copy of the article)
Trang 6The cells take up the plasmid, and if the
plas-mid contains a selectable marker, scientists
can identify the cells that have successfully
taken up the plasmid
v Gene Expression
Once inside the target cells, the plasmid can
replicate along with the host cell's DNA
If the plasmid contains a gene of interest under
the control of a promoter, the host cell can
ex-press that gene This leads to the production of
the protein encoded by the gene In vaccine
development, the plasmid can express an
anti-gen, allowing the immune system to recognize
and build immunity against it
v Harvesting the Product:
After gene expression or any other intended
application, scientists can harvest the product
(e.g., protein, therapeutic effect, immune
re-sponse) for further analysis or use
3.2 Micro Projectile Bombardment (Biolistic)
Method
As represented in Fig (4), the microprojectile
bombardment method is also called particle
accel-eration or gene gun delivery It is the direct
meth-od for transferring the foreign genes to the target
cells using heavy metal particles coated with
ex-ogenous DNA It involves coating tiny particles (microprojectiles) with the desired genetic material and then propelling them into the cells using a high-pressure device, such as a gene gun Upon impact, the DNA-coated particles are taken up by the cells, facilitating genetic transformation In this physical method of gene transfer, a gene gun de-vice is used to bombard genes to target cells In this method, the plant cells are placed beneath the gene gun, and the antigen gen bombardment at high pressure penetrates the plant cells [32-35]
3.3 Electroporation Method
This method, as represented in Fig (5), is also
known as the electro-permeabilization method This is the microbiological technique in which an electrical field is applied to the cells to increase their permeability In this method, the plant mate-rial is incubated in a buffer solution containing DNA and subjected to a high voltage electric pulse
by which the DNA migrates, and a pore is induced
in the plasma membrane These pores carry anti-gen anti-genes to the plant cells This technique is used
for all cereal crops like rice, maize, wheat etc [34,
36]
3.4 Chimeric Virus Method
A chimeric virus is a virus that contains genetic material derived from two or more distinct viruses These plant viruses are genetically modified to
Table 2 A comparison between traditional and edible vaccines is given as follows
i The edible vaccines are the transgenic plants that provide oral immunization against a particular disease The traditional vaccines contain the killed or attenuated form of virus antigen, providing systemic immunization
ii It provides both systemic as well as mucosal immunity It provides only systemic immunity
iii It is administered orally and directly stimulates the immune system It cannot directly stimulate the immune system
iv No syringe is required for the vaccine administration A syringe is essential for vaccination
v It is easily affordable for the poor people of developing nations It is too expensive, so poor people cannot afford the vaccines
vi It doesn't spread any environmental pollution The process of traditional vaccine manufacturing involves environmental
pollution
vii Its production of edible vaccines does not produce any toxic
chemical substances Traditional vaccines produce toxic chemicals in plants
viii No professional help is required for the vaccine administration Without an experienced doctor, it is impossible to administer the vaccine
ix No sterilization, purification, or processing is required The sterilization, packaging, and storage of traditional vaccines are very
expensive
x It is easily stored at room temperature Marinating a cold temperature is required for the storage of vaccines
Trang 7Edible Vaccines Recent Patents on Biotechnology, XXXX, Vol XX, No XX 7
Fig (3) Plasmid /vector carrier system (A higher resolution / colour version of this figure is available in the electronic copy of
the article)
Fig (4) Micro Projectile bombardment (Biolistic method) (A higher resolution / colour version of this figure is available in
the electronic copy of the article)
Trang 8Fig (5) Electroporation method (A higher resolution / colour version of this figure is available in the electronic copy of the
article)
carry particular genes and used to infect their
natu-ral hosts In these edible plants, the cloned genes
expressed themselves to varying degrees in
vari-ous edible parts of the host plant Particular viruses
can be redesigned to represent fragments of
anti-genic proteins on their surfaces, like cauliflower
mosaic virus (CaMV), alfalfa mosaic virus,
tobac-co mosaic virus, tobac-cowpea mosaic virus, tomato
bushy stunt virus, and potato virus [33-34,37]
These chimeric viruses can serve as the basis for
vaccines or help researchers study virus
interac-tions and mechanisms For instance, in the
devel-opment of vaccines, the chimeric virus can
stimu-late an immune response against a particular
path-ogen while lacking the harmful effects of the
orig-inal virus
4 EDIBLE VACCINES: CHALLENGES OR
CONSTRAINTS
Although the plant expression system has
sev-eral applications for human and veterinary vaccine
production, only a few vaccine candidates are in
clinical trials [6] Commercial human vaccines are
unavailable due to low levels of expression, low
efficacy, and a lack of knowledge about the prop-erties of plant-made antigens and production sys-tems The following are some of the challenges or constraints with plant-based vaccines [36, 37]:
• DNA modification
• Poor immunogenicity
• Dosage Flexibility
• Glycosylation and Allergenicity Alterations
• Degradation
• Spoilage
• Transgenics Generation Time
• Environmental and Human Health Risks
• Acceptance by peoples Edible vaccines, a groundbreaking concept in immunization, hold immense promise in revolu-tionizing how we prevent infectious diseases In-stead of traditional injections, they are adminis-tered through the consumption of genetically mod-ified plants or fruits, offering the potential for
Trang 9eas-Edible Vaccines Recent Patents on Biotechnology, XXXX, Vol XX, No XX 9
ier and more accessible vaccination However,
while the concept is tantalizing, it is not without its
significant challenges and constraints One of the
primary challenges faced by edible vaccines is the
complex regulatory landscape Developing
genet-ically modified organisms (GMOs) for vaccine
production requires stringent safety testing to
en-sure their suitability for human consumption and
minimal environmental impact Regulatory
agen-cies worldwide must establish comprehensive
guidelines for developing, producing, distributing,
and labelling edible vaccines Navigating this
reg-ulatory maze is time-consuming and costly, often
acting as a significant barrier to progress in this
field [38] Stability and dosage control are
funda-mental concerns when it comes to edible vaccines
The stability of vaccine antigens within the plant
or fruit matrix is critical for their efficacy Factors
such as environmental conditions, pests, and plant
age can influence antigen stability Moreover,
en-suring consistent dosage control in every fruit or
plant is challenging, potentially leading to
variabil-ity in vaccine effectiveness among individuals
Allergenicity is another pressing issue associated
with edible vaccines Genetically modifying plants
to produce vaccine antigens may introduce new
proteins that could provoke allergic reactions in
some individuals Extensive allergenicity testing is
essential to identify and mitigate potential risks,
but achieving complete certainty is difficult [39]
Storage and distribution of edible vaccines are
more challenging than their traditional
counter-parts Traditional vaccines are stored under
con-trolled conditions, ensuring their stability and
effi-cacy In contrast, edible vaccines are exposed to a
range of environmental conditions during storage
and transportation Safeguarding the integrity of
the vaccine in different climates and logistics
sys-tems is a formidable task that needs effective
solu-tions Public perception and acceptance represent a
substantial constraint for edible vaccines Some
individuals harbor concerns about consuming
ge-netically modified organisms, and there may be a
lack of understanding or trust in the technology
Successful adoption of edible vaccines hinges on
effective public education and communication to
build trust and address misconceptions Cost and
scalability are practical constraints that cannot be
ignored Developing and producing edible
vac-cines can be expensive, particularly during the
ear-ly stages Scaling up production to meet global
demand necessitates substantial infrastructure and investment Cross-contamination between genet-ically modified crops and non-GMO crops poses ecological risks that demand robust containment strategies Unintended consequences for ecosys-tems and agriculture must be averted Assessing the long-term safety of consuming edible vaccines
is paramount [38-40]
5 PATENTS ON EDIBLE VACCINES
Vaccines have long been essential in preventing the spread of infectious diseases and protecting global health Traditional vaccines are typically administered through injections, requiring trained personnel, cold storage, and proper disposal of needles However, recent advancements in bio-technology have paved the way for a groundbreak-ing concept: edible vaccines This innovative ap-proach involves producing vaccines in genetically modified plants, where the plant tissues become the delivery system This paper explores the con-cept of the production process of edible vaccines and their potential benefits, challenges, and future prospects The production of edible vaccines in-volves isolating the DNA sequence encoding a specific surface antigen from a pathogen This gene is then fused with a plant-specific promoter, ensuring the antigen's expression in transgenic plants Using various techniques like Agrobacte-rium-mediated transformation or biolistic particle bombardment, the modified gene is introduced
in-to plant cells, integrating inin-to their genetic
materi-al As the plant grows, it synthesizes the desired antigen in its edible parts, such as fruits, leaves, or seeds Once consumed, the plant-based vaccine stimulates the immune system, producing protec-tive antibodies against the targeted pathogen De-spite the promise of edible vaccines, several chal-lenges need to be addressed Regulatory concerns, public acceptance, and the potential for unintended environmental effects are critical issues that re-quire careful consideration Additionally, develop-ing edible vaccines for complex diseases requirdevelop-ing multiple antigen components remains a significant
challenge [41-69] Table 3
6 FUTURE OF EDIBLE VACCINES
The future of edible vaccines depends upon the various types of physical and social factors, some
of which are listed below:
Trang 10Table 3 List of edible vaccine Patent
Year Patent Number
1 Toshiyuki Sasagwa, Hideki Tohda, Yuko Hama Edible vaccine 2009 US 2009/0017063 A1
2 Toshiyuki Sasagwa, Hideki Tohda, Yuko
3
Sayed Sartaj Sohrab, Esam Ibraheem Ahmed
Ashar, Sherif Aly Abdelkhalek Elkafrawy,
Ayman Talaat Abbas Abdelhad, Edward P
Rybicki, Emmanuel Aubrey Margolin,
Development of an edible vaccine 2022 US 2022/0054628 A1
4 Kenneth John Piller, Kenneth Lee Bost Edible vaccines expressed in soybeans 2018 US 10,030,250 B2
5 Dominic Man-Kit LAM, Yuhong XU
Oral vaccines are produced and administered using edible microorganisms, including lactic acid bacterial
strains
2013 US 2013/0004547 A1
6 Heli Salmela, Dalial Freitak Edible vaccination against microbial pathogens 2021 US 2021/0275658 A1
7 Henry Daniell Expression of protective antigens in transgenic
chlo-roplasts and the production of improved vaccines 2014 US 2014/0294895 A1
8 Moshe Flaishman, Avi Pearl, Sara Gol-obowicz Transgenic ficus, a method for producing the same and use thereof 2012 US 8,148,603 B2
9 Takeshi Arakawa, William H.R Langridge Methods and substances for preventing and treating autoimmune disease 2002 AU 750623 B2
10 Dominic Man - Kit Lam, Olivia Yee - Yee Lam, Han Lei
Edible vaccines expressed in yeast for preventing and treating infectious diseases, including hepatitis b, in
humans
2020 US 10,793,866 B2
11 Guy Cardineau, Hugh Mason, Joyce
VanEck, Dwayne Kirk, Amanda Walmsley
Vectors and cells for preparing immunoprotective compositions derived from transgenic plants 2005 US 2005/0048074 A1
12
Yoshikazu Yuki, Hiroshi Kiyono, Takachika
Hiroi, Tomonori Nochi, Fumio Takaiwa,
Hidenori Takagi, Lijyun Yang, Kazuya
Su-zuki, Hiroyasu Ebinuma, Koichi Sugita,
Saori Kasahara
Rice plants having vaccine genes transferred
13 Yoseph Shaaltiel, Einat Almon Mucosal or enteral administration of biologically
active macromolecules 2017 EP2 441 840B1
14 Dionisius Elisabeth Antonius Florack, Hen-drik Jan Bosch Chimeric carrier molecules for the production of mucosal vaccines 2008 US 2008/0286297 A1
15 Fumio Takaiwa, Hidenori Takagi
Method of accumulating allergen-specific T-cell antigen determinant in plant and plant having the antigen determinant accumulated therein
2007 US 2007/0136896 A1
16 Dominic Man-Kit Lam, Yuhong Xu Immunoprotection by oral administration of
recombi-nant lactococcus lactis mini-capsules 2012 US 2012/0276167 A1
17 Henry Deniell Chloroplasts engineered to express pharmaceutical
proteins in edible plants 2016 EP2 141 981B1
18 Mee Chye, Hong Li, Sathiskumar Ramalin-gam, Leo Poon, Joseph Peiris
Genetically modified plants comprising SARS-CoV viral nucleotide sequences and methods of use thereof
for immunization against SARS
2006 US 2006/0053516A1
(Table 3) Contd…