What are different types of vaccines? Write method of preparation of small pox vaccine.
There are 4 main types of vaccines:
Live-attenuated vaccines
Inactivated vaccines
Subunit, recombinant, polysaccharide, and conjugate vaccines
Toxoid vaccines
Small pox vaccine is prepared by two methods 1) By using animals 2) By using Eggs
By using Animals : it is done in following steps
Selection of Animals: Healthy Sheep or calves selected and kept in an isolated area for
10-14 days under observation, it should be free from diseases.
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Preparation of animal for scarification (Abdomen and flanks are scrubbed, washed and
disinfected).
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Inoculation
(Light incisions are made on clear skin by scarifier, seed vaccine is inoculated in that
area)
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Incubation
(Incubate for 7-9 days, kept clean and aseptic, pustules are formed on line of
Scarification).
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Collection of viruses
(Abdomen and flanks are washed with sterile water. The Pustules are withdrawn
aseptically)
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Purification( mixed with equal volume of glycerin, cool and finely ground and store at -
10°C
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Filling and sealing (filled in final container and sealed aseptically)
By using eggs:
Hen egg is used
(Which is incubated after 12 days)
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Small cut on the shell
(exposed chorio-allantoic membrane)
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In this membrane, viruses are inoculated
(by seed of known potency )
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Cut was sealed by flap or paraffin wax
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Again incubate for 72 hours
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Using aseptic condition, shell is removed and chorio-allantoic membrane is
separated
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Contents are added in normal saline solution at 0° C
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Add 50 % glycerin
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Material is ground to produce homogenized suspension.
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Transfer to suitable sterile container and freeze dried