immunization with vaccine
TRANSCRIPT
Immunization
Immunity
Specific defensesImmunity
Passive immunityActive immunity
Following clinical infection
Following subclinical infection
Following vaccination Following administration ofImmunoglobulin or antiserum
Transfer of maternal Antibodies Through milk
Transfer of maternal Antibodies Through placenta
natural
acquired
Immunizing agents
Immunizing agents
antiseraimmunuglobulinsvaccines
Purpose of Vaccination
Protect the individual from disease.Reduce the severity of disease.Protect the community.Eradication of the disease.
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Reduce the burden of disease.
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Luis Fermín Tenorio,
the last polio case in the Americas
Peru, 1991
Ali Maouw Maalin,last case of
smallpox (Somalia,1977)
Vaccines are the most cost-effective tools for preventing death and disability from infectious disease
The value of VaccinesThe value of Vaccines
Basic concept of vaccines6
Deliver to the body some part or all of the disease organism that IMITATES the pathogen but is not pathogenic. Induce protective immune response.
Polysaccharide
Surface proteins
Intracellular proteins
Toxins
Entire organism• live (attenuated)• killed
LPS
capsular
Tools available to develop a Tools available to develop a processprocess
Growthof
Virus, Yeastor Bacteria
Clarification
Inactivation
PL
Formaldehyde
Eggs
Bacterial / Yeast
Fermentation
Cell culture
Depth filter
Crossflow filtration
Centrifuge
PurificationConcentration ++
Crossflow filtration
Chemicalprecipitatio
n
Ultracentrifugation
Chromatography
Ion exchangeHydrophobic
AffinitySize exclusion
Cross-flow filtration
The majority of the feed flow travels tangentially across the surface of the filter, rather than into the filter. The principal advantage of this is that the filter cake (which can blind the filter) is substantially washed away during the filtration process, increasing the length of time that a filter unit can be operational.
It can be a continuous process.
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Vaccine manufactureVaccine manufactureAntigen ProductionAntigen Production
EggsEggs– InfluenzaInfluenza
Bacterial / Yeast Bacterial / Yeast fermentationfermentation
– Whole organism (e.g. Cholera)Whole organism (e.g. Cholera)– Subunit vaccines (e.g. Capsular Subunit vaccines (e.g. Capsular
polysaccharide, Tetanus and polysaccharide, Tetanus and Diphtheria toxoid)Diphtheria toxoid)
– Genetically engineered proteins (e.g. Genetically engineered proteins (e.g. Hepatitis B and HPV vaccines)Hepatitis B and HPV vaccines)
Cell cultureCell culture– Viral vaccines either whole virus or Viral vaccines either whole virus or
subunitsubunit– Genetically engineered proteinsGenetically engineered proteins
FormulationAntigen
presentation
ISCOMS
ADJUVANTS
VIRUS LIKE PARTICLES
VIROSOMES
CONHNHCO(CH2)4CONHNHOC- DTVi-CPS
CONJUGATES Combining Combining antigen(s)antigen(s)
Combining with Combining with adjuvantadjuvant
StabilizersStabilizersPreservativesPreservatives
Cryo-protectantsCryo-protectants
Fill and Finish
A conjugate vaccine is created by covalently attaching a poor (polysaccharide organism) antigen to a carrier protein (preferably from the same microorganism).
Immune stimulating complexes (ISCOMs) are spherical open cage-like structures that are spontaneously formed when mixing together cholesterol, phospholipids and Quillaia saponins under a specific conditions.
the ISCOM-Matrix is simply mixed with the antigen post-manufacturing, the antigen can also be incorporated into the structure.
Adjuvant: The word “adjuvant” comes from the Latin word adiuvare, meaning to help or aid. "An immunologic adjuvant is defined as any substance that acts to accelerate, prolong, or enhance antigen-specific immune responses when used in combination with specific vaccine antigens."
Virosome: A virosome is a drug or vaccine delivery mechanism consisting of unilamellar phospholipid membrane (either a mono- or bi-layer) vesicle incorporating virus derived proteins to allow the virosomes to fuse with target cells. Virosomes are not able to replicate but are pure fusion-active vesicles.
A cryoprotectant is a substance used to protect biological tissue from freezing damage (antifreezers).
Conventional cryoprotectants are glycols, such as ethylene glycol, propylene glycol, and glycerol.
Types of Vaccines13
Types of vaccines
Live vaccinesAttenuated live vaccinesInactivated (killed vaccines)ToxoidsPolysaccharide and polypeptide (cellular
fraction) vaccinesSurface antigen (recombinant) vaccines.
Types of vaccinesLivevaccines
LiveAttenuated vaccines
KilledInactivated vaccines
Toxoids Cellular fraction vaccines
Recombinant vaccines
•Small pox variola vaccine
•BCG•Typhoid oral•Plague•Oral polio•Yellow fever•Measles•Mumps•Rubella•IntranasalInfluenza•Typhus
•Typhoid•Cholera•Pertussis•Plague•Rabies•Salk polio•Intra-muscular influenza•Japanise encephalitis
•Diphtheria•Tetanus
•Meningococcal polysaccharide vaccine•Pneumococcal polysaccharide vaccine•Hepatitis B polypeptide vaccine
•Hepatitis B vaccine
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Inactivated Toxins
Exotoxin Gram negative and
gram positive bacteria.
Heat Labile. Protein. Secreted by the
bacteria.
Endotoxin Gram negative
bacteria. Heat stable. Lipopolysaccharide. Firmly bound to the
bacteria outer membrane.
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Toxoid
- Not a vaccine against the organism.- Inactivation of toxin by chemical
(formalin) or heat treatment.Vaccine against pathogenic exotoxinTetanus, diphtheria, (pertussis?), anthrax?
Purify toxin then chemically inactivate (toxoid) Risk of incomplete inactivation. TT (Tetanus toxoid), DT.
Genetically modify toxin so non-toxic CRM (diphtheria), mLT (cholera, ETEC)
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Whole Bacteria or Whole Bacteria or Virus VaccinesVirus Vaccines
Cholera bacteria Polio
virus
Live vaccines
Live vaccines are made from live infectious agents without any amendment.
The only live vaccine is “Variola” small pox vaccine, made of live vaccinia cow-pox virus (not variola virus) which is not pathogenic but antigenic, giving cross immunity for variola.
Subunit
Purify a protein or proteins from pathogen
Selective presentation of 'protective' antigens Pertussis
Pertussis toxin + filamentous haemagglutinin + pertactin (no LPS)
Influenza (subunit) Mainly haemaglutinin + neuraminidase
Disadvantages Requires growing the pathogen and purifying
protective (antigens) subunits.
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Bordetella pertussisBordetella pertussis
Filamentous haemagglutinin
Pertactin
Pertussis toxin a 69 kD outer membrane protein (OMP).
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Different forms of Polysaccharide
LPS Capsular polysaccharide
Polysaccharide
Many bacteria produce a strain-specific capsular polysaccharide on their surface.
Antibody to these antigens are protective. Streptococcus pneumoniae, Haemophilus Type
B, Typhoid (Vi). Can be easily purified.Immunogenic in older children / adults.But poorly immunogenic in infantsT-cell independent responses
Short lived Low antibody responses
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Conjugate Conjugate VaccinesVaccines
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NHNHCO(CH2)4CONHNH
Exoprotein A (rEPA)
SpacerC=O
C=O
Vi
Capsular Polysaccharide
Vi Conjugate vaccineVaccine against Typhoid Fever
Vector Vaccine
A vector vaccine is a vaccine which is introduced by a vector e.g. vaccinia virus.
The vaccinia virus as a live vaccine led to the globally eradication of the smallpox virus.
The genome of the vaccinia virus has been completely sequenced.
The vaccinia virus is generally nonpathogenic.
INTRODUCTIONINTRODUCTION
DNA vaccine is DNA sequence used as a vaccine.
This DNA Sequence code for antigenic protein of pathogen.
As this DNA inserted into cells it is translated to form antigenic protein. As this protein is foreign to cells , so immune response raised against this protein.
In this way ,DNA vaccine provide immunity against that pathogen.
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Recombinant VaccinesRecombinant Vaccines
S. cerevisiae
E.coli
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Express protective antigen in safe easy-to-grow organism Hepatitis B (HBsAg expressed in yeast) HPV (papilloma L1 expressed in yeast)
VIRUS LIKE PARTICLES
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Recombinant Vaccine
The gene coding for HBsAg was discovered in 1970.
The gene has been inserted into a yeast cell.
As the yeast cell grows it produces large amounts of HBsAg.
The HBsAg is extracted and purified then incorporated into the vaccine.
Recombinant DNA modified organismsLive Vectors
Cloning of genetic material from one organism into another.
The non virulent parent organism expresses the antigens of the cloned genetic material.
A vaccine would produce a response against the introduced antigen as well as the original organism.
Recombinant DNA modified organisms
Vaccinia virus expressing papilloma virus antigens on its surface.
DNA vaccines Vs Traditional DNA vaccines Vs Traditional vaccinesvaccines
Uses only the DNA from infectious organisms.
Avoid the risk of using actual infectious organism.
Provide both Humoral & Cell mediated immunity
Refrigeration is not required
Uses weakened or killed form of infectious organism.
Create possible risk of the vaccine being fatal.
Provide primarily Humoral immunity
Usually requires Refrigeration.
DNA vaccines Traditional vaccines
HOW DNA VACCINE IS MADEHOW DNA VACCINE IS MADE
Viral gene
Expression plasmid
Plasmid with foreign gene
Recombinant DNA Technology
Bacterial cell
Transform into bacterial cell
Plasmid DNA
Plasmid DNA get Amplified
Plasmid DNA Purified
Ready to use
METHODS OF DELIVERYMETHODS OF DELIVERY
Syringe delivery:-
Either intramuscularly
or
Intradermally
ContdContd....Gene gun delivery-:
Adsorbed plasmid DNA
into gold particles
Ballastically accelerated
into body with gene gun.
HOW DNA VACCINE WORKSHOW DNA VACCINE WORKS
BY TWO PATHWAYSENDOGENOUS :- Antigenic Protein is presented by
cell in which it is produced
EXOGENOUS :- Antigenic Protein is formed in
one cell but presented by
different cell
HOW DNA VACCINES WORKHOW DNA VACCINES WORK
Muscle Cells Plasmid DNA
+
mRNA
Antigenic Protein
Antigenic Peptides
MHC-I
Plasmid DNA
Nucleus
ENDOGENOUS ENDOGENOUS PATHWAYPATHWAY
Multiply
Memory T cells
T- Helper Cell
EXOGENOUS EXOGENOUS PATHWAYPATHWAY
Antigenic Protein come outside
Phagocytosed
Antigen Presenting Cell
Antigenic Peptides
T- Helper Cell
Cytokines
Activated B-Cell Memory B-Cell
Plasma B-Cell
Memory Antibodies
MHC-II
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Recombinant Vaccine
ADVANTAGESADVANTAGES
Produce both Humoral & cell mediated immunity.
Focused on Antigen of interest.Long term immunity.Refrigeration is not required.Stable for storage.Produced more quickly.In larger quantities.Free from infectious virus particles.
DISADVANTAGESDISADVANTAGES
Limited to protein immunogen only.
Extended immunostimulation leads to chronic inflammation.
Some antigen require processing which sometime does not occur.
Genetic ToxicityGenetic Toxicity
Integration of DNA vaccine into host Genome
Insertional mutagenesis Chromosome instability
Turn ON Oncogenes
Turn OFF Tumor suppressor genes
FUTURE PROSPECTSFUTURE PROSPECTS
Plasmid with multiple genes provide immunity against many diseases in one booster.
DNA vaccines against infectious diseases such as AIDS, Rabies, Malaria can be available.
Why no HCV vaccine
HCV has different genotypes: Since hepatitis C has at least six genotypes, several different vaccines would be needed to protect against each genotype.
HCV mutates very easily: This means that some of its genetic code can change a little bit when it replicates itself. The result is a virus that keeps its genotype, but is different enough to confuse a vaccine.
There is no effective small animal model or cell culture system:This makes vaccine development very challenging because researchers can't see how the virus really works in a natural environment. Really, scientists don't truly understand the whole life-cycle of the hepatitis C virus because infecting liver cells (called hepatocytes) is very difficult.
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