Vaksin Dan Sera(7)

Vaksin dan sera

Vaksin: Substansi yg bersifat antigen:-mikro-organisme:

-bakteri- virus- adjuvan

Sera: Substansi yang bersifat sebagai antibodi:-protein:

-Imunoglobulin (serum imun)- monoklonal antibodi

-Vaksin dalah substansi biologik yg dapat meningkatkan sistem imun untk penyakit tertentu

-Vaksin mengandung sejumlah kecil agen yg menyerupai mikroorganisme tertentu

- Agen akan menstimulir sistem imun tubuh untk mengenal agen asing tersebut , membunuhnya , dan mengingatnya,

- Sehingga bila ada agen yg sama tersebut masuk kedalam tubuh dengan mudah akan dibunuhnya

Vaksin

Fungsin vaksin

• Sebagai profilaktik• Mencegah serangan infeksi mikroba

patogen• Sebagai therapeutik

• Untuk pengobatan penyakit kanker

1. Mampu meningkatkan respon imun terhadap penyakit tertentu (TB-CMI; bakteriIg)

2. Mempunyai daya proteksi yg lama– Idealnya masa hidupnya lama

3. Aman – Tdk menimbulkan penyakit

4. Stabil– Tdk berubah dlm penyimpanan seblm diberikan

5. Relative murah

Syarat vaksin yang baik

Mekanisme

A. Vaccines contain antigens (weakened or dead viruses, bacteria, and fungi that cause disease and infection)B. B cells to produce antibodies, with assistance from T-cellsD. macrophages engulf them, process the information contained in the antigens,C. and send it to the T-cells so that an immune system response can be mobilized

Jenis vaksin yg telah diproduksi

• Hepatitis B virus • Hepatitis A virus • Influenza • Measles • Mumps • Polio • Rubella • Rabies • Yellow Fever • Varicella Zoster

Develop vaccines against infectious diseases such as tuberculosis, malaria, AIDS and rotavirus.

Jenis vaksin

Vaksin

Vaksin hidup/live vaccineLive attenuated organismsHeterologous vaccines Live recombinant vaccines

Vaksin mati/killed vaccineSubcellular fractionsRecombinant proteins

Vaksin hidup

• Attenuated organisms – Organisme dilemahkan (kurang virulen) dengan

cara invitro mis.dg. perlakuan pemanasan (mutans), dengan bahan kimia

– Org. Selektif mutans dlm tubuh bereplikasi lambat dan tidak virulen, tdk menimbulkan gejala klinis

– Menimbulkan respons imun

Vaksin hidup

• Heterologous vaccines– Organisme yang mirip dengan target vaksin tetapi kurang

virulen, yg dpt berbagi antigen dengan organisme virulen– Strain vaksin tersebut bereplikasi dalam tubuh penerima

dan menstumir terbentuknya respon Ab, bereaksi silang dengan organisme virulen (target)

– Misalnya: virus cowpox dan vaccinia- mirip virus variola

Agen penyakit smallpox

Vaksin rekombinan

-Menggunakan rekayasa genetika:

-Gen yg telah terkode sebg imunogenik protein dari suatu organisme disisipkan kedalam genome organisme lain (mis virus vaccinia)

-Organime tersebut mengekspresikan gen yg baru gen baru tersebut dinamakan rekombinan

- Bila diinjeksikan pada individu akan bereplikasi dan mengekspresikan sejumlah protein asing yg cukup utk menginduse respon imun spesifik dr protein tersebut

Vaksin rekombinan

Vaksin mati/killed vaccine

Organisme patogen di inaktivkan dengan cara:

- Pemanasan- bahan kimia:

beta-propiolactone or formaldehyde

These vaccines are not infectious and are therefore relatively safe.

Subcellular fractions:

- Protektive imun biasanya terjadi langsung dari satu atau dua jenis protein dari organisme patogen

-Memungkinkan utk menggunakan protein murni dari org yg dimurnikan utk digunakan sebagai vaksin

prosedur:MO dibiakkan dan kemudian di inaktivkanProtein yg diinginkan dimurnikan dan dikonsetratkandr suspensi kultur.

Prosedur (vaksin virus polio)

Step 1Use the tissue culture to grow new viruses.

Step 2Use the purifier to isolate the polio viruses.

Step 3Use formaldehyde to kill the viruses.

Step 4Fill the syringe with the killed

DoneThe polio vaccine is complete.

Step 1Use the growth medium to grow new copies of the Clostridium tetani bacteria

Step 2Isolate the toxins with the purifier.

Step 3Add aluminum salts to the purified toxins.

Step 4Fill the syringe with the treated toxins.

DoneThe tetanus vaccine is complete.

Prosedur (vaksin tetanus toxin)

Vaksin protein rekombinan (killed vaksin)

-Immunogenic proteins of virulent organisms may be synthesized artificially by introducing the gene coding for the protein into an expression vector, such as E-coli or yeasts.

The protein of interest can be extracted from lysates of the expression vector, then concentrated and purified for use as a vaccine.

The only example of such a vaccine, in current use, is the hepatitis B vaccine.

Prosedure protein rekombinan (vaksin HiB)

Step 1Use the tweezers to pull out a segment of DNA from the hepatitis B virus.

Step 2Add the segment of DNA to the DNA of a yeast cell (which is in the yeast culture

Step 3Use the purifier to isolate the hepatitis B antigen produced by the yeast cells.

Step 4Fill the syringe with the purified hepatitis B antigen.

DoneThe hepatitis B vaccine is complete.

Attributes - Killed vaccines1.Immune response •poor;  only antibody - no cell immediated immune response. •response is short-lived and multiple doses are needed. •may be enhanced by the incorporation of adjuvants into the vaccine preparation

2. Safety •Inactivated, therefore cannot replicate in the host and cause disease. •Local reactions at the site of injection may occur.

3. Stability •Efficacy of the vaccine does not rely on the viability of the organisms. •These vaccines tend to be able to withstand more adverse storage conditions.

4. Expense •Expensive to prepare.

Adjuvants Certain substances, when administered simultaneously with a specific antigen, will enhance the immune response to that antigen. Such compounds are routinely included in inactivated or purified antigen vaccines.

Adjuvants in common use: 1. Aluminium salts

-First safe and effective compound to be used in human vaccines.

-It promotes a good antibody response, but poor cell mediated immunity. 2. Liposomes and Immunostimulating complexes (ISCOMS) 3. Complete Freunds adjuvant is an emulsion of Mycobacteria, oil and

water ; -Too toxic for man -Induces a good cell mediated  immune response.

4. Incomplete Freund's adjuvant as above, but without Mycobacteria. 5. Muramyl di-peptide

Derived from Mycobacterial cell wall. 6. Cytokines

IL-2, IL-12 and Interferon-gamma.

DNA Vaccines

DNA vaccines are at present experimental, but hold promise for future therapy since they will evoke both humoral and cell-mediated immunity, without the dangers associated with live virus vaccines.

The gene for an antigenic determinant of a pathogenic organism is inserted into a plasmid.  

This genetically engineered plasmid comprises the DNA vaccine which is then injected into the host.  

Within the host cells, the foreign gene can be expressed (transcribed and translated) from the plasmid DNA, and if sufficient amounts of the foreign protein are produced, they will elicit an immune response.

Sera (antibodi)

The advantages of antibody-based therapies include versatility, low toxicity, pathogen specificity, enhancement of immune function, and favorable pharmacokinetics;

The disadvantages include high cost, limited usefulness against mixed infections, and the need for early and precise microbiologic diagnosis.

The potential of antibodies as anti-infective agents has not been fully tapped. Antibody-based therapies constitute a potentially useful option against newly emergent pathogens.

Antibody therapy Chemotherapy

Immune serum Human MAb

Specificity Narrow Narrow Broad

Source Animals Humans

Tissue culture Bioreactor

Fermentation

Fermentation Chemical synthesis

Toxicity High Low Low

Cost High High Low

Administration Difficult Easy Easy

Pharmacokinetics Variable Consistent Consistent

Mechanism of action

Antimicrobial Immune

enhancement Toxin neutralization

Antimicrobial Immune

enhancement Toxin neutralization

Antimicrobial

Serum therapy, human MAbs, and antimicrobial chemotherapy