Quality Control Of Vaccine PDF

QUALITY CONTROL OF VACCINE Vaccines Definition:  “Preparation of killed microorganisms, living attenuated organisms, that is administered to produce or artificially increase immunity to a particular disease”. OR  “A vaccine is a biological preparation that improves immunity to a partic...

QUALITY CONTROL OF VACCINE Vaccines Definition:  “Preparation of killed microorganisms, living attenuated organisms, that is administered to produce or artificially increase immunity to a particular disease”. OR  “A vaccine is a biological preparation that improves immunity to a particular disease”. OR  Vaccines are microbial preparations of killed or modified micro organisms that can stimulate an immune response in the body to prevent future infection with similar micro organisms.  A vaccine typically contains an agent that resembles a disease-causing microorganism, and is often made from weakened or killed forms of the microbe, its toxins or one of its surface proteins.  The agent stimulates the body's immune system to recognize the agent as foreign, destroy it, and "remember" it, so that the immune system can more easily recognize and destroy any of these microorganisms that it later encounters.  Non living vaccines provide protection for only a limited time, and a repeated vaccination is required to maintain protection against typhoid fever, cholera, plague and typhus.  Active immunization with living agent is generally preferable to immunization with killed vaccines because of a superior and more long-lived immune response. For eg: a single vaccination of measles, rubella, or mumps is sufficient to produce a long-lasting if not permanent immunity. Contraindication:  Vaccines are contraindicated in following conditions. 1. Conditions in which immune response may be depressed such as during therapy with corticosteroids, anti neoplastic agents, immunosuppressive agents or radiation. 2. In patients with immunoglobulin deficiency. 3. In patient with active infection.  Active immunization may cause fever, malaise, and soreness at injection sites.  Some reactions are relatively specific for a particular vaccines such as arthralgia following rubella vaccine.  Convulsion following pertusis vaccine.  Allergic reactions may results either from the organism constituting the vaccine or from a protein incorporated into the vaccine during manufacturing, for example egg protein from chick embryo tissue cultures.  Careful history of a patient should be taken before vaccination to detect possible hypersensitivity to the protein to be injected. TYPES OF VACCINES 1. Live, attenuated vaccines 2. Inactivated vaccines 3. Subunit vaccines 4. Toxoid vaccines 5. Conjugate vaccines 6. DNA vaccines 7. Recombinant vector vaccines 1. Live, Attenuated Vaccines:  Live, attenuated vaccines contain a version of the living microbe that has been weakened in the lab so it can’t cause disease.  Because a live, attenuated vaccine is the closest thing to a natural infection, these vaccines are good “teachers” of the immune system.  Example: Vaccines against measles, mumps, and chickenpox 2. Inactivated Vaccines:  Scientists produce inactivated vaccines by killing the disease-causing microbe with chemicals, heat, or radiation.  These vaccines are more stable and safer than live vaccines.  Because dead microbes can’t mutate back to their disease-causing state.  Example: Vaccines against influenza, polio, hepatitis A, and rabies. 3.Subunits Vaccines:  Instead of the entire microbe, subunit vaccines include only the antigens that best stimulate the immune system.  In some cases, these vaccines use epitopes the very specific parts of the antigen that antibodies or T cells recognize and bind to.  Because subunit vaccines contain only the essential antigens and not all the other molecules that make up the microbe.  Example: Plague immunization. 4.Toxoid Vaccines:  For bacteria that secrete toxins, or harmful chemicals, a toxoid vaccine might be the answer.  These vaccines are used when a bacterial toxin is the main cause of illness.  Scientists have found that they can inactivate toxins by treating them with formalin. Such “detoxified” toxins, called toxoids, are safe for use in vaccines.  Example: Crotalus atrox toxoid is used to vaccinate dogs against rattlesnake bites. 5.Conjugate Vaccines:  ‘Conjugate’ means ‘connected’ or ‘joined’.  With some bacteria, to get protection from a vaccine you need to train the immune system to respond to polysaccharides (complex sugars on the surface of bacteria) rather than proteins.  But in the early days of polysaccharide vaccines it was found that they did not work well in babies and young children.  Researchers discovered that they worked much better if the polysaccharide was attached (conjugated) to something else that creates a strong immune response.  In most conjugate vaccines, the polysaccharide is attached to diphtheria or tetanus toxoid protein.  The immune system recognises these proteins very easily and this helps to generate a stronger immune response to the polysaccharide.  Example : Haemophilus influenzae type B vaccine. 6.DNA Vaccines:  Still in the experimental stages, these vaccines show great promise, and several types are being tested in humans.  DNA vaccines take immunization to a new technological level.  These vaccines dispense with both the whole organism and its parts and get right down to the essentials: the microbe’s genetic material.  Example: Influenza vaccine. 7.Recombinant Vector Vaccines:  Recombinant vector vaccines are experimental vaccines similar to DNA vaccines  But they use an attenuated virus or bacterium to introduce microbial DNA to cells of the body.  “Vector” refers to the virus or bacterium used as the carrier.  Example : DPT ANTI VIRAL VACCINES 1. Small pox vaccine 2. Rabies vaccine 3. Yellow fever vaccine 4. Influenza virus vaccine 5. Poliomyelitis vaccine 6. Measles vaccine 7. Rubella virus vaccine 8. Mumps vaccine BACTERIAL VACCINES  Typhoid vaccine  Cholera vaccine  Plague vaccine  Pertussis vaccine  Tuberculosis vaccine  Meningococcal polysaccharide vaccine  Pneumococcal vaccine Quality control tests  Staining test  Sterility test  Inactivation test  Pyrogen test  Freedom from abnormal toxicity Staining test  Take approximately 10 ml of the test sample centrifuge it in a centrifuge tube for 30 minutes.  After that take the sediment or the bottom portion and spread it on a glass slide, dried it or heat it over a flame.  The smear is then stained by the Gram’s method & unless otherwise specified, examined microscopically at an approximately 1000 fold magnification.  Criteria for judgment  As specified in monographs. Sterility test 1. Immersion (Direct inoculation) For Bacteria:  Take clean & dried petri dishes of 10 cm in diameter, add about 15ml of a fluid thioglycolate medium in it, at not more than 45C.  Allow it to solidify.  Spread the preparation on the surface of the solidified medium of a petri dish.  Prepare at least two such petri dishes, using the same dilution & incubate at 30C-35C for 14 days.  Count the number of colonies that are formed. For fungi  Take clean & dried petri dishes of 10 cm in diameter.  Add approximately 15 ml of a liquified soyabean casein digest medium, at not more than 45C.  Allow it to dry.  Spread the preparation on the surface of the solidified medium of a petri dish.  Prepare at least two such petri dishes, using the same dilution & incubate 20C-25C for 14 days.  Count the number of colonies that are formed. 2. Membrane filtration  Use membrane filters which are 50mm in diameter & having nominal pore size not greater than 0.45µm.  Transfer 10 ml or a quantity of each dilution containing 1 gram of the preparation under examination to each of two membrane filters & filter immediately.  The filter is then transferred into the appropriate medium (Soya bean casein digest medium for fungi & fluid thioglycolate for bacteria).  Then the membrane is incubated for 14 days.  Observe the no: of colonies. Inactivation test  Each purified bulk material shall be tested in mice for effective inactivation of the virus before the addition of preservative & other substances.  The test should be performed with undiluted purified bulk material, injected intra-cerebrally into at least 20 mice, each weighing between 15 & 20 grams.  These mice shall be observed for 14 days.  Any symptoms caused by the virus shall be confirmed by. immuno-flourescence assay (a standard virologic technique to identify the presence of antibodies by their specific ability to react with viral antigens expressed in infected cells)  At the end of the observation period, no cytopathetic (refers to structural changes in host cells that are caused by viral invasion) effect should be observed. Pyrogen test  The test involves measurement of the rise in body temperature of rabbits following the IV injection of a sterile solution of the substance under examination. Test Animal: Healthy adult rabbits of either sex, each weighing not less than 1.5 kg fed on a balanced diet are used for the test. Procedure:  Insert a clinical thermometer into the rectum of each rabbit & normal reading of body temperature are taken prior to the injection of test solution.  Two such readings are taken at an interval of 30 minutes & the mean is calculated.  This reading is taken as initial temperature of the rabbit.  The test solution is injected into the ear vein of the rabbit.  Record the temperature of each rabbit at an interval of 30 minutes for 3 hours after the injection.  The difference between the maximum temperature & initial temperature is taken as response. Interpretation of result No of Cumulative Individual temp: Temp: rise in Result tests no: of rabbits rise in C group ( C ) 1 3 Less than 0.6C Less than 1.4 Passes 2 8 (3+5) Less than 0.6 in at Less than 3.7 Passes least 5 out of 8 If the first test fails than repeat the test on additional 5 rabbits Freedom from abnormal toxicity Test in mice  Take 5 healthy mice weighing 17-22 g.  Inject 1 human dose not more than 1ml intra-peritoneally.  Observe the mice for 7 days.  If one animal dies repeat the test.  Preparation passes the test if no animal dies in the second group. Test in guinea pigs  Take 2 healthy guinea pigs weighing 250-350 g.  Inject 1 human dose not more than 5ml intra-peritoneally.  Observe the guinea pigs for 7 days.  If one animal dies / shows ill repeat the test.  Preparation passes the test if no animal dies in the second group.