Vaccination

Questão	Responda
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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	Criado por Florence Edwards mais de 7 anos atrás