•An introduction to Vaccinology

•Vaccine history and types

•Epidemiologic basis of Vaccinology

•Role of combination vs. single vaccines

•The immune responses to the pathogen & vaccine

development

•Immunology of Vaccines

•Antigen and Vaccine Delivery Strategies

•Determinants of Vaccine Availability

•Vaccine development strategies: New approaches

•Live versus attenuated vaccines

•Role of multinational companies in vaccines production

•DNA as vaccine

•Peptide & Subunits vaccine

•Adjuvants in vaccines

•Population Genetic analysis: immunity

to vaccine

•Recombinant vaccine

•Animal models of vaccine testing

•Vaccine Delivery Systems

•Practical issues in relation to trials

•Ethical issues related to clinical

evaluation of vaccines

•Vaccine safety

•Review of vaccines in current use

•Vaccine-economics

•Future of Vaccines/Vaccination

Course Contents

Part 2: Principles of Vaccine Design

Immunologic Memory: T and B Cells memory

• Antigen Processing and Presentation by MHC Class I, II, and Nonclassical

Molecules

• Understanding the Mucosal Immune System for Better Mucosal Vaccine Design

PART 1 : INTRODUCTION• Definition• History • Types• Combination vs single vaccine

Course Contents

Part 3: ANIMAL MODELS FOR VACCNE TESTING

• Utility of Mouse Models in Vaccine Design and Development,

• Utility of Nonhuman Primate Models for Vaccines,

Part 4: Delivery Systems•Transcutaneous Immunization via Vaccine Patch Delivery System•Needle-free Jet Injection for Vaccine Administration•Oral Vaccines: An Old Need and Some New Possibilities Adjuvants:

Part 6: Regulatory Considerations•Regulatory Issues•Role of international companies•Vaccine economics

Part 5: Evaluating Vaccine Efficacy

• Trials in human and practical issues

PART 7: Population genetics and vaccines

• Ethical issues

• Vaccine safety

VACCINE DELIVERY SYSTEMS

VACCINE DELIVERY SYSTEMS

1. VIRAL VECTORS BASED

2. NON VIRAL

VACCINE DELIVERY SYSTEMS

• MUCOSAL DELIVERY OF VACCINES• LIPOSOMAL DELIVERY SYSTEMS• VIROSOMES DELIVERY SYSTEMS• POLIMERIC NANOPARTICLE DELIVERY SYSTEMS• DENDRIMER-BASED DELIVERY SYSTEMS• NEEDLE-FREE DELIVERY• EDIBLE VACCINES• DNA VACCINES:

Nanopatch A stamp-size patch similar to an adhesive bandage contains about 20,000 microscopic projections per square inch. When worn on the skin, it will deliver vaccine directly to the skin, which has a higher concentration of immune cells than the muscle tissue does, which is one of the tissues where injections commonly deliver vaccines.

1. Dermal administration by nanopatches thus increases the effectiveness of vaccination,

2. requiring less vaccine than injection.

LIPOSOMAL DELIVERY SYSTEMS

•Viruses, proteins, glycoproteins, nucleic acids, carbohydrates, and lipids can be entrapped and targeted at cellular and subcellular level for evoking immune responses•Diphtheria liposomal vaccine shows good immunogenicity and tolerance in humans

• Liposomes and their derivatives “lipoplexes” (liposome/DNA complexes) are hollow spherical constructs of phospholipid bilayers capable of entrapping hydrophilic moieties in the aqueous compartment and hydrophobic moieties in the lipid bilayers with cholesterol imparting rigidity to the bilayer.

VIROSOMES DELIVERY SYSTEMS

Virosomes represent vesicular systems into which antigens can be loaded into virosomes or adsorbed onto the virosomal surface through hydrophobic interactions

VIROSOMES DELIVERY SYSTEMS• Virosomes are small spherical

unilamellar lipid membranes of nucleocapsid including vesicles (150 nm) embedded with viral membrane proteins such as hemagglutin and neuraminidase of influenza virus but devoid the genetic material of the source virus.

• Once they have delivered the antigens, the virosomes are completely degraded within the cells

DENDRIMER-BASED DELIVERYSYSTEMS•Dendrimers are branched, synthetic polymers with layered Architectures. to bind the DNA and get it into the cell.

•Dendrimers, available under the trademark name of “Starburst” serve as nonviral gene transfer agents, enhancing the transfection of DNA by endocytosis and, ultimately, into the cell nucleus.

•A novel approach for the treatment of renal cell carcinomas uses a chimeric molecule comprising a granulocyte macrophage colony stimulating factor (GM-CSF) attached to a G250 kidney cancer specific antigen which is transfected in to the cancerous cell by the use of dendrimer

DENDRIMER-BASED DELIVERYSYSTEMS

POLIMERIC NANOPARTICLE DELIVERY SYSTEMS

Polymeric nanoparticles because of their size are preferentially taken up by the mucosa associated lymphoid tissue. They are extensively reviewed for nasal and oral delivery of vaccines

EDIBLE VACCINES

CONCLUSION

• Vaccine drug delivery systems are gaining popularity these days due to the benefits they offer.

• As they avoid the need to administer booster doses and provide a long term therapy in small dose.

• Needle free technologies, Edible vaccines on the other hand open an attractive avenue for the oral delivery of vaccines.

VECTORS IN VACCINE DELIVERY

• To transfer the desired gene into a target cell, a carrier is required. Such vehicles of gene delivery are known as vectors.

• 2 main classes– Viral vectors– Non viral vectors

Cancer Vaccines

CD4 T Cell

TCR

TCR

Class II MHC

Class I MHC

ActivatedDendritic Cell

Tumor Antigen

Cytokines = HELP

CD8 T Cell

Activated CD8 T Cells Traffic to Tumor and Lysis Cells

Burch et al, 2000; Small et al 2000; Fong et al, 1997.

PSA

LFA-3 ICAM-1 B7-1

Co-Stimulatory Molecules

Target Antigen

Plasmid DNA

Vaccinia VirusFowlpox Virus

rV-PSA-TRICOMrF-PSA-TRICOM

Packaging Cell Line

Vaccine

Viral Vaccines – Same Idea: But Starting At A Different Step

PSA= prostate-specific antigen.Madan et al, 2009; Sonpavde et al, 2011; Drake, 2010.

ProstVac VF

ProstVac VFCD4 T Cell

TCR

CD8 T Cell

TCR

Class II MHC

Class I MHC

Epithelial Cells

ACTIVATED

CD8 T Cell

Madan et al, 2009; Sonpavde et al, 2011.

The only cell-based therapy currently approved for the treatment of prostate cancer.

1. he antigen prostatic acid phosphatase (PAP), which is present in 95% of prostate cancer cells, and

2. an immune signaling factor granulocyte-macrophage colony stimulating factor (GM-CSF) that helps the APCs to mature.

Basic research

Gene therapy

vaccines

APPLICATIONS

MOST COMMON VIRAL VECTORSRetroviruses

Adenoviruses

Adeno-associated viruses

Herpes simplex viruses

can create double-stranded DNA copies of their RNA genomes. Can integrate into genome. HIV, MuLV, Rous sarcoma virus

dsDNA viruses that cause respiratory, intestinal, and eye infections in humans. Virus for common cold

ssDNA viruses that can insert their genetic material at a specific site on chromosome 19

dsDNA viruses that infect a neurons. Cold sores virus

ADENOVIRUSES

As opposed to Lentiviruses, adenoviral DNA does not integrate into the

genome and is not replicated during cell division.

with adenoviruses, which cause respiratory, gastrointestinal and eye infections,

they trigger a rapid immune response with potentially dangerous

consequences. To overcome this problem scientists are currently

investigating adenovirusesto which humans do not have immunity.

1. their basic biology has been studied extensively

2. the viral genome can accommodate large heterologous transgene

insertions,

3. they readily infect quiescent and dividing cells,

4. they can be amplified to high titers and

5. they have previously been shown to be relatively safe for use in

humans.

ADENO-ASSOCIATED VIRUSES

AAV is not currently known to cause disease and consequently the virus

causes a very mild immune response. AAV can infect both dividing and

non-dividing cells and may incorporate its genome into that of the

host cell. These features make AAV a very attractive candidate for creating

viral vectors for gene therapy

HERPEX SIMPLEX VIRUS VECTOR

VIRAL VECTORS1) RETROVIRUS VECTOR SYSTEM

• The recombinant retroviruses  have the ability to integrate into the host genome in a stable fashion.

• Can carry a DNA of size – less than 3.4kb

• Target cell - dividing

number of FDA-approved clinical trials such as the SCID-X1 trial.

either be replication-competent or replication-defective..

involves the requirement for cells to be actively dividing for transduction.

cells such as neurons are very resistant to infection and transduction by

retroviruses.

There is concern that insertional mutagenesis due to integration into the

host genome might lead to cancer or leukemia

Retroviruses

Retro virus

GP2-293

GP2xTERT11 PRODUCER CELL LINE ENVELOPE CONSTRUCT

PRIMARY T CELLS

PACKAGED TERT RECOMBINANT VECTOR

N S

Staining with anti-NGFR ab beads

A PRACTICAL EXAMPLE OF RETROVIRAL VECTOR