Vaccines
H.Sidra Yasin (BIOT 412)
Learning objectives
What are the Methods to produce the vaccines
 How we can modify the Vaccines
 What are the Routs of administration of vaccines
 What are the Types of vaccines
 What is Reverse vaccinology and its purpose
 Summary of all topics with conclusion

General Method to produce the
vaccine
Vaccine composition
Following are:
Component
Purpose
Example
Adjuvants
enhance the immune response to a
vaccine
aluminium salts
Preservatives
prevent bacterial or fungal contamination
of vaccine
thiomersal
Additives
stabilise vaccines from adverse
conditions such as freeze-drying or heat,
thereby maintaining a vaccine’s potency
gelatine
Residuals from
manufacturing
process
Inactivating agents
formaldehyde
Antibiotics - prevent bacterial
contamination during manufacturing
process
neomycin, streptomycin,
polymyxin B
Egg proteins- some vaccine viruses are
grown in chick embryo cells
Yeast proteins
Immunisation Department, Centre for Infections
influenza, yellow fever
HepB vaccine
Modifiers of vaccines
Modifiers of vaccines
Adjuvants
 Boosters

Adjuvants

Chemical substance that can be added to a
vaccine in order to enhance the immune
response to the vaccine.
Types
1.
Freund’s Adjuvant
Aluminum Hydroxide
3. Aluminum Phosphate (Alum)
2.
Boosters

Periodic “booster”
administration must be
given in order to
strengthen and lengthen
the duration of immunity
Routs of administration
Routes

Intradermal administration.
◦ Three types are;
intravenous
intramuscular
subcutaneous.

Oral administration.
◦ Vaccine is usually given in
liquid form.
◦ Foods

Intranasal administration.
Types of vaccines
Types of vaccines
Traditional
1. Types
A. Inactivated
B. Live
C. Attenuated
2. Pathogens
A. Bacteria
B. Virus
C. Parasites
Recombinant vaccines
1.
2.
3.
4.
5.
Subunit Vaccines
peptide vaccines
Attenuated Vaccines
Vector Vaccines
Bacterial Antigen
Delivery Systems
Traditional vaccines
Live, Attenuated Vccines




Act like natural infection
Live, but weakened, viruses or bacteria
Altered organisms, either genetically or
chemically but non pathogenic
Example:
Attenuated virus vaccine for yellow fever,
which utilizes the YF17D strain, a weakened
form of the wild virus.
Advantages
•
•
Single dose sufficient to
induce long-lasting immunity
Strong immune response
Local and systemic immunity
Others…

Polio and Adeno
•
•
Disadvantages
•
•
•
•
•
Potential to revert to virulence
Contraindicated in
immunosuppressed patients
Interference by viruses or
vaccines and passive
antibody
Poor stability
Potential for contamination
Live, Attenuated vaccines
Inactivated Vaccines
 Either:
Suspensions of whole intact killed
organisms
◦ e.g. whole cell Pertussis, Influenza, Rabies, HepA
 Or:
Acellular and sub-unit vaccines
◦ e.g. Acellular Pertussis vaccine contains between 2-5
components of the whole cell Pertussis bacteria
Inactivated vaccines
1.whole



actual pathogen
killed, either by a heat treatment or chemically
Salk vaccine for polio, which utilizes whole
polioviruses that have been inactivated by
formaldehyde.
2.Fractional
Protein based; Toxoids
Stimulates the antibody mediated response
Exotoxins

Toxoids are vaccines which consist of exotoxins

Immunity against the toxins, but not necessarily the bacteria that produce
the toxins.

Examples:

Botulinum antitoxen

Diphtheria antitoxen

Pertusis

Tetanus toxoids

Protein based; Subunit
Pathogenic agent
 Use components of pathogenic organism instead of whole
organism
 Advantage: no extraneous pathogenic particles i.e DNA
 Disadvantage: Costly
 Examples
o HSV
Method of production
o Tuberculosis
o Foot -and-Mouth Disease virus (FMDV)

Polysaccharide based; pure

pure cell wall polysaccharide from
bacteria
Polysaccharide based; conjugate




o
o
o
o
Polysaccharide linked to a carrier protein
More potent
lacks long term immunological memory
Protect against:
Hib
Pneumococcal diseases
Tetanus
Diphtheria
Advantages
•
•
•
•
•
Stable
Constituents clearly defined
Gives sufficient humoral
immunity if boosters given
No mutation or reversion
Can be used with immunodeficient patients
Disadvantages
•
•
•
•
•
•
•
Many vaccinees do not raise
immunity
Shorter lasting immunity
Boosters needed
Need several doses
Adjuvant needed
Failure in inactivation and
immunization with virulent
viruses
Others…
Inactivated vaccines
Possible Limitations of Traditional Vaccine
Production

Not all infectious agents can be grown in culture

Animal/human cell culture expensive if needed

Yield of viruses from cultures can be low

Safety precautions for culture of live agents

Insufficient killing/attenuation of agents

Reversion of attenuated agents

Traditional vaccines are less diverse
New Strategies




Delete virulence genes
Use live nonpathogenic carriers for immunization
(unrelated pathogenic agent)
Clone antigenic determinants into alternative host
Address autoimmune system response/problems
So!!!
Recombinant vaccines
Types
Subunit Vaccines
2. Peptide vaccines
3. DNA Vaccines
4. Vector Vaccines
1.
Peptide vaccines
Use discrete portion (domain) of a surface protein as Vaccine.
These domains are ‘epitopes’
 antigenic determinants
 are recognized by antibodies
Use highly immunogenic carrier molecule
With carrier proteins
DNA Vaccines



DNA vaccines consist of plasmids that contains genes for
certain types of antigens.
Once administered, the plasmid is taken up by the
target cell and the genes are expressed.
The cell then either excretes the antigen or displays it on
an MHC-I molecule.
Genetic Immunization
Delivery of a gene for the antigen to a host organism
•
Use vector containing cDNA from viral protein/
eukaryotic promoter
•
Inject into muscle
POTENTIAL
•
Eliminates purification of antigen
•
Protein is modified post-translationally
Chimeric Vaccines



Consist of attenuated viruses have been engineered to
carry antigens from multiple types of pathogens.
The yellow fever vaccine has been engineered to carry
antigens from HIV, different types of bacteria, malaria,
even cancer.
immunity against several different diseases with one
administration.
Human Diseases for Which Recombinant Vaccines Are
Currently Being Developed
Vaccine Production methods
Vaccine Production Methods
Manufacturing strategies:
◦ In-vivo
◦ In-vitro
◦ Chemical Synthesis
 Some
vaccines can be produced using any one
of the three methods while for other vaccines,
only one method will work.
In-Vitro


Here, using recombinant
DNA technology,
vaccines can be
produced in yeast
cultures, bacterial
cultures, or cell cultures.
Recombinant vaccines,
such as chimeric and
Attenuated virus/bacteria
vaccines, are produced in
this manor.
In-Vivo

Embryonated Chicken eggs
are commonly used as in
producing flu vaccines.

Vaccines, like anti-idiotype,
can also be produced in lab
animals, such as mice.

There are even some
species of plant, such as
bananas, that have been
genetically engineered to
produce a vaccine.
Chemical Synthesis

Produced in a lab.

Vaccines that utilize
synthetic peptides as
well as conjugated
lipids and
polysaccharides

Used in combination
with either in-vivo or
in-vitro production.
Summary!!!
Thank you!