7977344
Description
Flashcards by Florence Edwards, updated more than 1 year ago
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Created by Florence Edwards
almost 8 years ago
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| Question | Answer |
| What is the function of passive immunisation? | Used to provide immunity to infection before animal can mount its own immune response |
| Give an example of a clinical application of passive immunisation | Tetanus anti-toxin |
| Describe how tetanus anti-toxin is produced | Immunise horse with formalin-treated tetanus anti-toxins Collect serum Purify immunoglobulin |
| How can tetanus anti-toxin antibodies from horses be given to other species? | Enzymatic cleavage to Fab fragments only (removal of Fc fragment) Reduces antigenicity to other species |
| What is a disadvantage of passive immunisation? | Pre-formed antibody prevents recipient immune response |
| What can be a problem with giving antibodies repeatedly for passive immunity? | Potential for hypersensitivity |
| What is active immunisation? | Administration of antigen to induce an immune response and immunological memory |
| What is the main function of vaccination? | Immunological memory - secondary, rapid immune response |
| How are vaccines normally stored? | Refrigerated at a particular temperature |
| Why is it important that a vaccine induces an appropriate immune response? | Different infections require varying proportion of humoral and cell-mediated immunity For example, viral infections require cell-mediated immunity |
| Why should a vaccine include multiple antigenic epitopes? | Stimulate multiple clones of T and B cells |
| Which antibodies are involved in cell-mediated immunity? | Restricted sub-class of IgG |
| Which antibodies are involved in humoral immunity? | IgG IgA IgE |
| What are the 2 main cytokines produced by Th1 cells? | IL-2 Interferon gamma |
| Which cytokine produced by Th1 cells inhibits Th2 cells? | Interferon gamma |
| What are the 4 main cytokines produced by Th2 cells? | IL-4 IL-5 IL-9 IL-13 |
| Which cytokines produced by Th2 cells inhibit Th1 cells? | IL-4 IL-13 |
| Give an example of a live virulent vaccine | Orf vaccine in sheep |
| What are live attenuated vaccines? | Reduce virulence of agent through genetic modification, chemicals or growth at certain temperatures |
| Do attenuated vaccines cause infection? | Low-grade infection induced which cannot cause disease |
| What are live heterologous vaccines? | Antigenically related but adapted to another species |
| Give an example of a live heterologous vaccine | Measles virus can be used in dogs to provide cross-immunity against distemper |
| What are killed or non-infectious vaccines? | Organism is antigenically intact but unable to replicate |
| Give 3 methods for killing agents for use in vaccines | Formalin Alcohol Alkylating agents |
| Are killed vaccines more likely to induce a humoral or cell-mediated immune response and why? | Th2 mediated humoral response Lack of a cell-mediated immune response as cannot infect cells |
| Why does the immune system not respond as effectively to killed vaccines? | Agent does not move around the body |
| What is meant by risk of return to virulence? | Attenuated agent could regain virulent properties by recombination with bacteria in the environment or animal |
| Which type of vaccine requires more doses? | Killed vaccines require more doses than live vaccines |
| Which type of vaccine requires an adjuvant? | Killed vaccines |
| Which type of vaccine is more stable? | Killed vaccines are more stable than live vaccines |
| How does replication allow live vaccines to induce better immunity? | Increasing antigenic challenge over days to weeks |
| How does location allow live vaccines to induce better immunity? | Immunological challenge is at a relevant anatomical site |
| Why do live vaccines contain more antigens? | Expressed as well as structural antigens |
| Why are live vaccines more able to stimulate cell-mediated immunity? | Intracellular replication |
| What are subunit vaccines? | Contain antigenic epitopes (structural proteins or specific metabolites) that induce protective immunity |
| Give an example of a subunit vaccine | Leukocell 2 Contains glycoprotein 70 extracted from feline leukaemia virus |
| Give 2 disadvantages of synthetic peptide vaccines | Low immunogenicity so require adjuvant Monospecific immune response |
| How are synthetic peptide vaccines produced? | Amino acid sequencers |
| What are GM vaccines? | Attenuate organism by modifying or deleting virulence genes |
| Give an example of a GM vaccine | Removal of thymidine kinase gene from swine herpesvirus |
| What are marker vaccines? | Allow differentiation between infected and vaccinated animals |
| What is IBR? | Infectious Bovine Rhinotracheitis |
| How is IBR diagnosed? | Antibody to glycoprotein E |
| How has a marker vaccine been developed against IBR? | Remove glycoprotein E gene from vaccine Can differentiate between infected and vaccinated animals |
| What is meant if a cow has no anti-glycoprotein E? | Seropositive due to vaccine |
| What is meant if a cow has serum anti-glycoprotein E? | Field exposure |
| What are recombinant vaccines? | Remove RNA from viruses that codes for antigenic epitope Protein can be synthesised and harvested from E.Coli |
| Describe the process by which recombinant vaccines are produced | RNA encoding viral antigen Reverse transcriptase converts to DNA Gene excised with restriction endonucleases Inserted into E.Coli plasmid Antigen harvested from E.Coli Mixed with adjuvant for vaccine |
| Give an example of a recombinant vaccine | Leucogen (Virbac) Recombinant feline leukaemia virus p45 antigen |
| Which 2 adjuvants are used in this vaccine? | Aluminium hydroxide Quil A |
| Why is an adjuvant required for recombinant vaccines? | Improve immunogenicity |
| How can recombinant organisms be used to transfer viral genes into host organisms? | Benign virus carrier Attenuated bacterial carrier |
| Why is canarypox virus a commonly used vector? | No infection in mammals |
| For which 2 vaccines is canarypox used as a vector in Europe? | Feline leukaemia virus Cat rabies |
| For which vaccine is canarypox used as a vector in the USA? | Distemper |
| Are recombinant bacterial vaccines available yet? | No |
| What is naked DNA vaccination? | Plasmid DNA used as vaccination Transfects host cells including dendritic cells Antigen presented in lymph node Strong T and B cell responses induced |
| Give 3 routes of administration for naked DNA | Intramuscular Mucosal Intradermal with carrier such as gold particles |
| Which barrier to vaccination may be overcome by naked DNA vaccination? | Maternally derived antibody |
| Give an example of a naked DNA vaccination used experimentally | Rabies glycoprotein gene given to dogs in bacterial plasmid |
| What is the advantage of naked DNA vaccination in terms of immunogenicity? | No adjuvant required |
| What is the advantage of naked DNA vaccination in terms of dosing? | Fewer doses required |
| What is meant by vaccine delivery via high pressure injection? | High pressure transdermal system |
| Which 2 cells are accessed by high pressure injection? | Epidermal Langerhans cells Dermal dendritic cells |
| In which species is aerosilisation commonly used to administer vaccines? | Poultry |
| What is a method of vaccine delivery specific to poultry? | In ovo |
| How are vaccines delivered in fish? | Immersion (water) |
| How can vaccines be used in cancer therapy? | Enhance immune response to some cancers which can increase survival time |
| What is the difference between core and non-core vaccines? | Core = all animals should receive Non-core = not every animal needs them |
| What percentage of animals need to be vaccinated for herd immunity? | 70% |
| How are young animals vaccinated and why? | Series of priming vaccines due to maternally derived antibody 12 month booster |
| What is DoI? | Duration of immunity |
| Which animals should vaccines NOT be given to unless specifically indicated? | Pregnant animals Sick or immunosuppressed animals |
| Why should vaccines not be given in pregnant animals? | Live attenuated vaccines can damage the foetus |
| Give an example of a disease for which vaccination records are a legal requirement | Rabies |
| Where can adverse reactions to vaccines be reported? | Veterinary Medicines Directorate |
| Why can the same dose of vaccine be given to differently sized dogs? | Same minimum antigenic dose required regardless of size |
| Give an example of a breed that does not always mount an effective immune response to vaccination | Rottweilers |
| Why is it important to read the 'claim' for which a vaccine is licensed? | Claim details expected efficacy of vaccine e.g. no infection versus less severe disease if infected |
| What are the 3 most common vaccine-associated adverse effects? | Transient post-vaccinal illness Transient post-vaccinal immunosuppression Local injection site reactions |
| What is a FISS? | Feline Injection Site Sarcoma Malignant tumour caused by injectable products |
| Give 4 hypersensitivity reactions that can occur due to vaccination | Angioedema Immune Mediated Haemolytic Anaemia Immune Mediated Thrombocytopenia Vasculitis caused by immune complexes |
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