Immunological products
1-Vaccines
2-Monoclonal
antibody
a) Production of bacterial vaccines
•1-clinical specimen or obtained as lyophilized culture is
cultivated in liquid suitable medium ?????
•2-The incubation conditions are adjusted.
•3-At the end of the growth period the cultures (from
different fermenters) are pooled to form a bulk harvest. Dangerous????
•4-Inactivation of the cultures, toxoids.
•5-Separation of the bacterial cells is often carried out by
centrifugation while ammonium sulphateis used to precipitate diphtheria and
tetanus toxoids.
b) Production of viral vaccines
•The growth medium.
•The skin of calves is used for smallpox
vaccine, the fertile eggs (chick embryo) for influenza and yellow fever and
cell cultures prepared from monkey kidney are used for rabies vaccine.
•The required virus is inoculated and the
living cells are incubated until the virus growth is maximal. The culture
fluids containing the virus are then harvested and pooled.
•Most modern viral vaccine.
•Attenuated ?????
•There are three important exceptions:
influenza, poliomyelitis and rabies.
Blending:
various components of the vaccine are mixed to form a final bulk, during this
step preservative and adjuvants are added.
Quality control of viral vaccines
•Vaccine formulations include constituents such as viruses and
bacteria.
•Since all vaccine batches are not the same, their content and
effects must be tested regularly at selected stages of production to monitor
safety and efficacy (potency).
Animals are generally used (in vivo)
in addition to in vitro procedures.
1)In process control:
2)Final product control:
In process control
•Carried out on starting materials and intermediates
Example:
•Quality control of diphtheria and tetanus toxoidsfor the
absence of free toxin due to inadequate detoxification with formalin.
•Titration of polio virus prior to inactivation to produce
inactivated polio vaccine.
Final product control
The final product should be tested for:
•Identity
•Potency
•Safety
•Identity tests: e.g., SDS PAGE, Western blot, immunologic
assay: agglutination precipitation
Potency assay
•Qualitative and quantitative assays are required to verify
that the batch of vaccine induces protective immunity.
•In live, attenuated vaccine material, the numbers of live
particles are determined by counting (viable count for bacteria) or by
titration (an in vitro process).
•For inactivated (killed) vaccine, each batch is tested in
vivo, and the animals are monitored to assure that the vaccine has the efficacy
expected in relation to its ability to stimulate the production of antibodies.
Antibodies are then assayed by vaccination of a gp of animals and titration of
blood samples for antibodies and comparaison with standard vaccin.
Safety tests
•Animals are used to detect any harmful effect or disease.
•Killed vaccine must be free from any living form.
•Toxoidsmust be free from any free toxin.