Unit 2 - Vaccines Flashcards
How do you prevent disease
Nutrition, hygiene, housing, transport, ventilation
What is immunoprophylaxis
Prevention of disease through the exploitation of the immune system
What are the two forms of immuno prophylaxis
Passive immune therapy which is short term, vaccination long term
Why is disease prevention important
Treatment may be unavailable, poorly efficacy, have unwanted side effects. Cheap in cost and performance for large animals due to disease may be reduced or eliminated. Eradication of some diseases may be possible by vaccination
What is a vaccine
A preparation of a week or killed pathogens such as a virus or bacteria, or of a portion of the pathogens structure that upon administration stimulates antibody production against a pathogen but is in capable of causing severe infection.
What does getting a vaccine result in
Active acquired immunity.
Why was a vaccine designed
To do you said to me in response which should be protective and most vaccinated animals.
What does vaccine protocol depend on
Varies depending on type of vaccines such as modified live or inactivated. Characteristics of the group to be vaccinated newborns versus adult, and characteristics of the infection route of exposure, local versus systemic, prevalence
What is the goal of vaccination
Production of memory cells which help the body respond much faster with a larger response if reexposed to the same antigen
What is the time period between vaccination on the creation of memory cells
2 to 3 weeks if the vaccine is injected, several days if given intranasally
What is considered an anamnestic or secondary response
When the body responds to the booster vaccine greater and much faster then after the first vaccine. The second vaccination will produce more memory cells against parvovirus and the body is primed.
How long did memory cells live
Memory cells again some diseases live a long time, while those for other diseases may have a relatively shorter lifespan. Since memory cells do not live forever we need to revaccinated animal to produce a new generation of memory cells.
What is duration of immunity
How long a sufficient number of memory cells live and how long the antibodies remain so that the animals still protected
What is herd immunity
If most of the population is immune that is heard of him unity. With heard immunity outbreaks are limited to sprout a cases because there are not enough susceptible individuals to support spread of epidemics. Heard immunity also protects unvaccinated individuals by preventing easy spread of disease. Important for animals that cannot be vaccinated
How do you produce a vaccine
By understanding the principal virulence mechanisms of the agent. Ability to grow the agent in vitro. Knowledge of the pathogenesis of the disease, including root of infection. Stability of the organisms antigens. mutability. Immunogenicity of the agent and its products.
What is an adjuvant
Immunological agent that enhances the immune response to a vaccine. Adjuvants may be crucial components of a vaccine, particularly inactivated and subunit types since these are often poorly immunogenic. Most live vaccines are not adjuvanted
What is a route of vaccination
The route of vaccination is biased the immune response that results. In general, parenteral routes favor induction of systemic immunity and mucosal roots favor Immune responses at the mucosal surface not absolute. Potent crossover responses can be achieved
What does a parenteral vaccine do to the body
Stimulates primary response by draining lymph nodes, memory cells home primarily to other peripheral nodes and spleen. Provides good systemic Immunity. Vigorous immunization may permits spill over to mucosal sites
What do mucosal vaccinations do
Stimulates local immunoresponse at site of administration, memory cells home to other mucosal sites. Vigorous immunization or modified live virus may also and do systemic response
How do you mass immunize
Aerosol spray, drinking water, water bath. More convenient and economical than individual immunization . Used widely and poultry industry and fishfarming.
What are the four types of vaccines
Live, attenuated vaccine. Modified live vaccines.
Inactivated vaccines,
subunit vaccines,
toxoid vaccines
Describe modified live vaccine
Contain a version of the living micro that has been attenuated in the lab so it cannot cause disease. Closely mimics an actual infection.
What does attenuated mean
Weakened
What do attenuated virus is due in the body
Replicate increasing the original dose and acting as a series of secondary booster immunizAtion.
Where are modified live vaccines derived from
Usually derived from mutations or Gene deletion. Can also be derived from naturally occurring strains of organisms that are of low virulent in the target species. The strains need to express antigens relevant for protection against the more Virulent cousin strains
What is the advantage to giving a modified live virus
One initial dose is usually sufficient, additional boosters may be required due to passive anti-body interference. More rapid protection then killed vaccines. Produces a wider spectrum of protection then killed vaccines. Less likely to cause allergic reactions or post vaccination lumps. Less susceptible to passive antibody vaccine block. Less expensive
What is the disadvantage to modified live viruses
May cause mild disease. Can become a carrier of modified virus and shut the virus. Cannot be used in immunosuppressed animals. Some risk of causing abortion or transient infertility. Must be handled and mixed with care
What is in inactivated or killed vaccine
Killed organism, organism components or organism byproducts. Organisms are killed by chemical treatment, irritation, heat. Killed vaccine products use a large amount of organisms to produce a sufficient immunoresponse
What are bacterin’s
Inactivated vaccines that contain kill bacteria alone or enriched with selected bacterial antigens. Immunity of short duration, usually less than one year. Gram-negative bacteria and have increased risk of producing anaphylactic vaccine reaction
What is a subunit vaccine
Type of killed vaccine that contains only part of the virus or other micro organisms. Use only antigenic fragments of a micro organism the best to stimulate immune response
Why are subunit vaccine safer
Because they cannot reproduce inside the recipient
What is the advantage of subunit vaccines
Because they only contain the essential antigens and not all the other molecules that make up the microbe, the chances of adverse reactions to the vaccine are lower
What are recombinant vector vaccines
Type of subunit vaccine. Hybrid vaccine virus which uses alive avirulent virus such as canary pox to carry and express relevant antigens from one or several other virulent viruses. Stimulate protective levels of immunity without undergoing replication in mammals.
What are toxoids
Used for bacteria that secrete toxins or harmful chemicals. These vaccines are used when a bacterial toxins is the main cause of illness. Bacterial toxins are in activated by formalin. such detoxified toxins are called toxoids and are safe for use in vaccines.
What happens when the immune system receives a vaccine containing a harmless toxoid
It learns how to fight off the natural tocsin. The immune system produces antibodies that lock onto and block the tocsin such as the tetanus toxoid