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
-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
Fungsi vaksin
• Sebagai profilaktik
• Mencegah serangan infeksi mikroba
patogen
• Sebagai therapeutik
• Untuk pengobatan penyakit kanker
Syarat vaksin yang baik
1. Mampu meningkatkan respon imun terhadap penyakit
tertentu (TB-CMI; bakteriIg)
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
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-cells
D. 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
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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 vaccine
Live attenuated organisms
Heterologous vaccines
Live recombinant vaccines
Vaksin mati/killed vaccine
Subcellular fractions
Recombinant 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 inaktivkan
Protein yg diinginkan dimurnikan dan dikonsetratkan
dr suspensi kultur.
Prosedur (vaksin virus polio)
Step 3
Step 2
Step 1
Use the tissue culture
to grow new viruses.
Done
The polio
vaccine is
complete.
Use
formaldehyde to
kill the viruses.
Use the purifier to
isolate the polio
viruses.
Step 4
Fill the syringe with the
killed
Prosedur (vaksin tetanus toxin)
Step 1
Use the growth
medium to grow new
copies of the
Clostridium tetani
bacteria
Done
The tetanus
vaccine is
complete.
Step 2
Isolate the
toxins with the
purifier.
Step 3
Add aluminum
salts to the purified
toxins.
Step 4
Fill the
syringe with
the treated
toxins.
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 Ecoli 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 2
Add the
segment of
DNA to the DNA
of a yeast cell
(which is in the
yeast culture
Step 1
Use the
tweezers to pull
out a segment
of DNA from the
hepatitis B
virus.
Done
The hepatitis B
vaccine is complete.
Step 3
Use the purifier to
isolate the hepatitis
B antigen produced
by the yeast cells.
Step 4
Fill the syringe with the
purified hepatitis B
antigen.
Attributes - Killed vaccines
1.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 cellmediated 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 (antibody)
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.
Serum therapy, human MAbs, and antimicrobial chemotherapy
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
Antimicrobial
Immune
enhancement
Toxin neutralization
Antimicrobial
Immune
enhancement
Toxin neutralization
Mechanism
of action
Antimicrobial