DEVELOPMENT OF ANTI-PARASITIC VACCINES AND THEIR APPLICATIONS
against cysticercosis and hydatid disease
against fasciolosis in sheep and cattle
against gastrointestinal worms
for the control of protozoans
scientific elements that will make vaccines
7.1. Parasite biology
7.2. Molecular biology
7.4. Vaccine trails
8. Where were the vaccines come from?
Over the last decade,the anti-parasitic
market has been the fastest growing sector of the overall 18 billion animal
health market. While the drugs for the treatment of parasites of livestock are
continuely developing and reformulating. By the increasing demands of consumers
there is fast development of safe and effective vaccines. Many anti-parasite
vaccines have been developed,eg the recombinant 45W and EG95 oncosphere
proteins against Taenia ovis and Echinococcus granulosis,respectively and the
Bm86 vaccine aginst Boophilus microplus etc. Live or attenuated live vaccines
are available for the control of avian concidiosis,taxplasmosis in sheep and
anaplasmosis in cattle,although molecular vaccines against protozoans are still
Vaccine against cysticercosis and hydatid
Cysticercosis caused by Taenia solium
instantly affects human health and rough porciculture. Cysticerci may present
in the central nervous system of human causing nuerocysticercosis,a very
dangerous and most occuring health problem in undeveloped countries. Total
number of cases and degree of strength of this disease in humans and pigs are
related to social factors(poor self hygiene,low sanitory issues,roughly raising
of pigs,open feaces) and some biological factors such as immunity,genetic
background and gender. The neccessary role of pigs as morally intermediate host
in the life cycle offers the need of involving with transmission through
vaccination of pigs. A vaccine which is very affective is based on three
synthetic peptides against pig cysticercosis has been successfully developed
and in experimental condition it is proved as very effective. The peptides from
which the vaccine is formed offer the possibility to seek a choice of antigen
production and delivery systems that may inhance the cost or benefit of this
and some other vaccines. The motivational results were obtained in tries to
produce large amounts of these peptides and inhanced its immunogenicity by
expression in recombinant filamentous phage(M13), in transgenic plants (carrot
and papaya) and related to bacterial immunogenic carrier proteins.
Vaccine against fasciolosis in sheep and
Vaccination of sheep against fasciola
hepatica with glutathione-S-transferase identification of mapping of antibody
epitopes on a three-dimensional model of the antigen.
introduction of GST as a vaccine against liver fluke infection was studied by
vaccinating sheep with GST from adults worms of Fasciola hepatica. When a GST
induced in naturally infected sheep an immunization induced by high antibody
response to GST as compared to poor or undetectable response to this Ag.
Throughout the experiment,all working of the fluke infection was monitered by
measuring RBCs hemoglobin level,the extent of damaging of liver and the fecal
egg output in the sheep. The above analysis indicated that the vaccinated
animals exhibited no anemia,reduction of liver damage and a low mean fecal egg
count as compared to the infected control group. The population of the GST
vaccine group demonstrated a 78% reduction in mean worm burdens compared to
control group. This shows that GST of adult Fasciola hepatica is a Ag that can
perfectly protect sheep against liver fluke infection. This suggests that the
immune response to GST is directed to the juvenile worm cause in reduction in
number of worms that can produce in the liver of the vaccinated animals.
Vaccine against gastrointestinal worms:
The ability of mammalian hosts to react to
gastrointestinal nematodes is a fuction of the age,nutrition and the
reproductive status,and the gene make up of the host and the capacity of the
external parasite to avoid,depressed or change the host reaction. Infection
causing nematodes larvae may be quickly expelled out from the immune host
before they can produce in the mucosa or in a naive or partially immune host
they may be expelled out at the after stage of their life cycle. The occurance
of immuno inflammatory cells in the mucosa is pre- required for full expression
of the rapid expulsion response. In vivo the stage specific antigens are
presented to the lymphoid apparatus is poorly understood. As an evident a
remarkable degree of stage specificity is used. In vitro, major
histocompatibility class ll elements stops T cell responses to nematode
antigen,in vivo, class ll major histocompatibility restriction to nematode
infection may also happen. New techniques for identifying nematode cuticle
antigens are now available and some of them produces protective responses
according to vaccine studies. The antigens which are secreted and the antigens
which are isolated from secretory organs are very protective, and are extracred
from whole worm isolation. These purified nematode antigens are sustained at
degree of stage specificity is demonstrable. This latter observation must be
taken in account when deciding vaccine strategies and so should the relative
abilities of different antigens to start the complex immuno inflammatory
responses in the mucosa.
Vaccines to ectoparasite:
Ectoparasites which are present in
livestock have great economic and social importance but their control is still
dificult. Over a decade ago the vaccination as a control measure was
established by the release of a special vaccine against the cattle tick
Boophilus microplus. The research is continued on ticks and other
ectoparasites. These have been many genomic technologies occuring for
ectoparasite vaccines. The number of most dangerous antigens is still very
small. Much hope has been expected of multi-antigen mix to deliver accuracy to
develop succesful vaccine with small experiments. Much knowledge has to be
exploe in regard to vaccine against ectoparasite. The need of vaccines and our
capacity to develop them can only increase.
Vaccine for the control of protozoans:
In domestic and companion animals protozoa
are responsible for morbidity and mortality. Immunity to natural infection is
established early in life by exposure to virulent parasite can prevent
infection. The basis of vaccine against theilerosis and avain coccidiosis is
that. Vaccination is not be practicle with disesses,such as a disease name
cryptosporidiosis,that firstly attack the immune-compromised or indiviuals with
an incompletly developed immune system. Passive immune therapy is used to
overcome these diseases. These include the use of bacteria or lower eukaryotes
to produce recombinant proteins in batch culture. Our lack of understanding of
immune mechanism to primary and secondary infection and the ability of many
protozoa to affect host immunity remain continue to developing effective
vaccines. This view examins the work made on developing proteins of
Eimeria,Giardia, Cryptosporidium,Toxoplasma,Babesia, and theileria. Attempts
are making to use these antigens for vaccinating animals against the relative
The scientific elements that will make
Parasites are everywhere,affecting
almost every aspect of their hosts including physiology,behaviour,life
histories and by entering the entire ecosystems. To overcome the affects of
parasites the host immune system is too much sophisticated and well known. But
the parasites develop many other ways to destroy their host. Host and parasites
are continuously fighting to defeat one and other. This fighting is very
dangerous for both parasites and their hosts. Over the last decades,many
principles from the fields of parasitology and immunology are being applied to
overcome the diversity of host-parastie phenomenon. This effort has led to
development of many kinds of fields of biology. People are studying many
ecological and immunological effects of parasitism. Advance studies shows that
the parasites are both harmful and useful effects. Parasitism is not only
harmful rather it can be major factor in maintinance of diversity in
populations and communities or even making us more social. Evolutionary
parasitology led us towards more fields such as immunology,genetics,sexual
selection,population,ecology,behavioural ecology and evolutionary biology.
Chemical basis of many living
organisms is explained by reductionist method of dissecting biological systems
into their constituent parts. But this approach is reached at limits.
Biological systems are very complex and have many properties that cannot be
explained by studying their each and every part. In the early days of molecular
biology the reductionist approach was high. By underustimating this complexity
on many areas of biomedical research including drug discovery and vaccine development.
The claim made by Francis Crick(1966)
that “the ultimate aim of the modern movement in biology is to explain all
biology in terms of physics and chemistry”. The theory says that the
biological systems are composed solely of atoms and molecules without the force
of “alien” or spiritual forces,it should be possible to explain
them,using the physioochemical properties of their every component down towards
the atomic level. The most change of the reductionist view is the believing
that is held by some neuroscientist that mental approach can be less to
chemical reaction occur in the brain.
Reductionist use a method to examine the
large systems are breaking them in small pieces and then examining their parts.
They concluded that each and every single part of the system is explaining much
more about whole system. This method of reductionist is an evident in molecular
biology. This was wrong that biological systems can be studied by physics and
chemistry. Their situation is similar to an art student.
Strong immune memory was responsible for
the protection of hepatitis B. Their is a link between specific
lymphoproliferation and immune memory. Antibody response shows the strength of
immune memory is called primary vaccination. Vaccine antigen dose and structure
are important influences in the development of immune memory.
1. Maternal and child health in rural
kenya,according to an epidemiological study.
2. The international AIDS vaccines
3. Chronic cryptosporidial diarrhea and
hyperimmune cow colostrum.
4. Therapeutic vaccine trails in Thailand.
5. Recruitment,screening and characteristics
of injection drug users HIV,vaccine trail,Bangkok,Thailand.
6. Surface display of clonorchis sinensis
enolase on bacillus subtilis spores potentializes an oral vaccine candidate.
7. Staphylococus aureus vaccine.
8. Mass vaccine compaign of typhoid.
9. Protection of cynomolgus macaques against
simian immunodeficiency virus by fixed infected cell vaccine.
Cellphone technology in a south african rural area in preparation for HIV
Where were the vaccines come from:
1. Typhoid vaccines come of age.
2. Fulfilling the promise of rotavirus
3. Salmonella enteria serovar Typhi live
4. DNA vaccines against cancer.
5. Naked DNA vaccines.
6. Vaccination and autoimmune rheumatic
7. Edible vaccines.
8. Heat shock proteins and cancer vaccines.
9. Vaccines for preventing typhoid fever.
infections and the vaccines to counter them.
1. The failed HIV Merk vaccine.
2. Vaccine development to prevent
3. Utilization of MHC class l transgene mice for
development of minigene DNA vaccines.
4. Development of a DIVA (differentiating
infected from vaccinated animals) strategy using a vaccine.
5. Size-dependant immunogenicity,therapeutic
and protective properties of nano-vaccines against tumors.
6. A research agenda for malaria eradication
7. In vivo primary of virus-specific cytotoxic
T lymphocytes with synthetic lipopeptide vaccine.
8. Development in foot and mouth disease
9. A riview of human vaccine research and
Contribution of CpG motifs to the immunogenicity of DNA vaccines.