Immunological preparations : National College of Pharmacy, Calicut Immunological preparations Slide 2: National College of Pharmacy, Calicut Immunity Natural – Part of
constitutional make-up Acquired – Added
during lifetime Active
(Developed and lost slowly) Passive
(Produced and lost quickly) Naturally
stimulated After clinical
infection After subclinical
infection By injection of antigen
(from mother) Artificially produced -by
( sera or human
immunoglobulin) Slide 3: National College of Pharmacy, Calicut Slide 4: National College of Pharmacy, Calicut Vaccines
containing antigens. Suspensions Solutions Killed microbes Live Attenuated
(Detoxified exotoxins) Vaccines - Classification : National College of Pharmacy, Calicut Vaccines - Classification Toxoids
Suspensions of microorganisms
Killed : Cholera, Pertussis, Plague, Typhoid-Paratyphoid A&B (TAB)
Attenuated: Bacillus Calmettee- Guerin (BCG)
Killed: Influenza, Measles, Poliomyelitis, Rabies
Attenuated: Measles, Poliomyelitis, Yellow fever, Smallpox
DNA vaccines Vaccines - Classification : National College of Pharmacy, Calicut Vaccines
Simple, Univalent eg: Cholera (Vibrio cholerae).
Mixed, multivalent eg: TAB (Sal.typhi, Sal paratyphi –A, Sal paratyphi-B). Vaccines - Classification DNA vaccines : National College of Pharmacy, Calicut DNA vaccines The use of DNA encoding specific virulence factors of defined pathogens to evoke an immune response.
The DNA is introduced by means of a transdermal gene gun and is transcribed by the recipient cells.
Accordingly the host responds as though it were in an infection.
Eventually the introduced DNA is lost from the recipient cells and antigen release ceases.
The approach has been used with some success in veterinary practice but not yet employed for human. History : National College of Pharmacy, Calicut History 1796 Edward Jenner published his book comparing vaccination (intentionally infecting humans with cowpox to induce resistance to smallpox)
Variola Classification : National College of Pharmacy, Calicut Classification Live vaccines - BCG
Killed vaccines – suspensions of bacteria or viruses that have been killed by heat by heat or by disinfectants such as phenol or formaldehyde.
Killed microbes can not replicate and cause infections - relatively concentrated suspensions to stimulate vaccinee’s immune system.
Even so these preparations are rather poor antigens are and to be somewhat toxic – hence they are given as divided doses.
These vaccines are hence take the advantage of secondary response, that occurs when a vaccine is administered to a vaccinee whose immune system is sensitized by a previous dose of the same vaccine. Eg: vaccines for whooping cough. Classification : National College of Pharmacy, Calicut Classification Toxoid vaccines: Tetanus toxoid, diphtheria. detoxified exotoxins. Eliminated toxicity without eliminating immunogenicity.
treatment with formalin (38% formaldehyde gas in water) – formol toxoid.
Bacterial cell component vaccines:eg: pneumococcal vaccines. They evoke a more specific immune response and avoid the injection of cellular components which makes no contributions to the immunity and may produce some undesirable side effects. Classification : National College of Pharmacy, Calicut Viral subunit vaccines: e.g.: influenza vaccine which consists of two subunits of influenza virus known as haemagglutinin and neuraminidase.
Rec. Vaccines: e.g. Rec. Hep. B vaccine.
Synthetic peptides: these are amino acid sequences and structures of some protein immunogens. Being a small portion of the entire protein immunogen, are likely to be poor antigens and so may be linked by physico-chemical methods to liposomes, mineral adjuvants, or possibly with tetenus toxoid to increse their immunogenicity.
Specific advantage: Absence of any ability to replicate in the tissues of the vaccinee, and possibility of Quality control by physico-chemical methods. Classification Bacterial vaccines : National College of Pharmacy, Calicut Bacterial vaccines Made either from the whole organisms or from the exotoxin. BCG (Bacille Calmitte-Guerin : National College of Pharmacy, Calicut Calmitte and Guerin are French biologists – they selected a cattle strain in the hope that it would be safer for men than human variety
Attenuation by 13 years of subculturing in a medium containing ox bile.
Due to unreliable absorption from the gut, the intracutaneous route is now used.
The living nature of the cells is demonstrated by the of a characteristic lesion at the site of injection. BCG (Bacille Calmitte-Guerin Preparation : National College of Pharmacy, Calicut Preparation Most important factor is detection and prevention of contamination of the product with virulent strains.
Lubeck disaster : death of children by injecting BCG vaccine produced from a virulent strain of human variety by mistake.
The laboratory suit is a completely self contained laboratory- no other organisms except the BCG strain are allowed. Preparation : National College of Pharmacy, Calicut Preparation The method of preparation of dead and living preprations are essentially the same except that for living preparations,
There is no sterilisation stage.
The viability of the cells must be maintained.
Standardization is on the basis of a viable count.
Each strain is carefully checked for
Freedom from pathogenicity.
freedom from variation
absence of contaminating organisms. Preparation : National College of Pharmacy, Calicut Preparation The organism is grown on a liquid medium for not more than 14 days. (older cultures are less efficient antigens).
Organisms are seperated by centrifugation. Washed and suspended in a vehicle that preserves antigenicity and viability for as long as possible.
The liquid vaccine has been replaced a freeze-dried form. Disadvantages of liquid Vaccine : National College of Pharmacy, Calicut Disadvantages of liquid Vaccine Even stored under ideal conditions, (2ºC-10ºC and protected from light), it rapidly deteriorates, due to loss of viability, and is unfit for use after 14 days from harvesting.
Because of short life, control tests including the vital test for virulence ( which takes six weeks to complete) cannot be finished, untill after the vaccine has been issued for use.
The compromise adopted to deal with such unsatisfactory situation was to attempt to stop further use of the batch as soon as failure of any test become known and to investigate the method of manufacture before any further batches were made. Freeze dried Vaccines : National College of Pharmacy, Calicut Freeze dried Vaccines When stored under the same specified conditions of liquid form, it can remain potent for at least an year. Therefore all the tests can and must be completed before issue. Disadvantages of freeze dried form : National College of Pharmacy, Calicut Disadvantages of freeze dried form The product may be so unsightly that it is pharmaceutically un acceptable.
The material may be so fluffy that part of the contents is lost when vacuum is released on the drying chamber.
It may be very difficult to obtain a clum-free homogenous suspension when the vaccine is reconstituted with sterile saline water. solutions : National College of Pharmacy, Calicut solutions The addition of a non ionic surfactant, such as polyoxyethylene in the growth medium cause the organism to grow throuhout the medium, instead of as tough surface pellicle. It eliminates clumping problems at all stages.
It improves the appearance.
Fluffiness can be reduced and reconstitution is assisted by inclusion of dextran in the suspending medium that was used for drying the cells. This medium also contains glucose which prevents excessive drying and in the correct concentration, allows retention of the optimum amount of moisture. BCG (Bacille Calmitte-Guerin : National College of Pharmacy, Calicut BCG (Bacille Calmitte-Guerin Suspension of living attenuated BCG strain of bovine organisms.
Source material: Live BCG cells from the cultures in liquid or solid media.
Cells centrifuged from medium
Resuspension in stabiliser
Freeze drying. BCG (bacille Calmitte-Guerin : National College of Pharmacy, Calicut Potency assay:
Viable count, Induction of sensitivity to tuberculin in guinea-pigs.
Exclusion of virulent mycobacterium, absence of excess dermal activity. BCG (bacille Calmitte-Guerin