Vaccines Flashcards
What is passive immunity?
Immunity achieved by preformed immunoglobulins from previously infected or immunized individuals. These antibodies provide immediate protection, but dissipate within a few weeks to months and do not generate memory.
What is one example of natural passive immunity?
Passive immunity generated through the natural transfer of maternal antibodies to the fetus through placental circulation and breast milk.
What is one example of induced passive immunity?
When a mixture of nonspecific antibodies reflecting previous exposures of plasma donors to various antigens are injected into patients to confer passive immunity.
What is IVIg?
Intravenous immunoglobulin is a last resort method of induced passive immunity where individuals are given a mixture of antibodies from multiple blood donors.
What is immunization?
The gaining of protective immunity through exposure to a pathogen (infection, vaccination).
What is vaccination
Intentionally exposing an individual to a pathogen with the intention of generating protective immunity.
What is natural active immunity?
Pathogen-specific immunity conferred through infection.
What is induced active immunity?
Pathogen-specific immunity conferred through vaccination.
What are four common ways that result in vaccination failing to immunize.
Administration, patient genetics, batch quality, and pathogen changes.
What are the three components of a vaccine?
The antigen (the target seen b the adaptive immune system), the adjuvant, and the route/dose.
What are live attenuated vaccines?
Vaccines containing a weakened form of the pathogen.
What are the strengths of live attenuated vaccines?
Attenuated microbes will multiply in the recipient, leading to a more robust immune response, both cellular and humoral. Usually lifelong immunity can be conferred with only 1 or 2 doses.
What are the weaknesses of live attenuated vaccines?
Attenuated vaccine strain could possibly revert back to an active form, so health professionals and immunocompromised individuals cannot be given this vaccine. These vaccines must also be refrigerated to stay potent.
What are killed virus vaccines?
Vaccines containing inactivated organisms or parts of them.
What are the strengths of killed vaccines?
They pose no risk of vaccine associated infection, and do not require refrigeration.
What are the weaknesses of killed vaccines?
They provide weaker and short-lived immune responses as the pathogen cannot replicate, and they are unable to actually infect the host. This necessitates several doses/ booster shots.
What are subunit vaccines?
Vaccines containing antigens from pathogen that best stimulate the immune system.
Do subunit vaccines elicit both cellular and humoral immunity?
No, they stimulate antibodies but no T cell responses.
What is one weakness of subunit vaccines?
They are not useful to confer immunity against pathogens that are antigenically diverse and variable.
What are toxoid vaccines?
A type of subunit vaccine used when a bacterial toxin is the man cause of illness. These vaccines contain chemically altered toxin or synthetically engineered harmless toxin.
What are engineered vaccines (recombinant vector vaccines)?
Vaccines that contain non-cytopathic or attenuated virus/bacteria with genes encoding microbial antigens.
What are the strengths of engineered vaccines?
They generate a true infection that induces both humoral and cellular immunity.
What are DNA and RNA vaccines?
Vaccines where a gene for an antigen of interest is clones into a bacterial plasmid that, upon injection into a host cell, uses host cell machinery to direct protein synthesis of the antigen.
What are the strengths of DNA and RNA vaccines?
They elicit “designer” immune responses, are low costing, and can induce both humoral and cellular immunity.
What are the three ways that adjuvants help in stimulating an immune response?
They prolong exposure of the antigen to the immune system, they promote uptake of the antigen (phagocytosis), and they activate the innate immune system by exhibiting co-stimulatory signals.
What are adjuvants usually made up of?
Usually made up of a mixture of oils, metal salts (alum), microbial cell wall components (mycobacteria), nucleic acids, and preservative (mercury).
How does alum stimulate the immune system?
It creates a depot effect, meaning the slow release of antigen to the immune system. Crystals from the depot are too large to phagocytose, irritating and increasing innate immunity.
What are two common routes of vaccine administration?
Subcutaneous or intramuscular, and intranasal or oral.
What are the benefits of innoculating individuals subcutaneously or intramuscularly?
Slow absorption of antigens, which will eventually be transported to local lymph nodes, resulting in the formation of memory cells that migrate throughout the entire body.
What are the benefits of innoculating individuals intranasally or orally?
Rapid absorption and involvement of mucosal lymphoid tissues, which does not generate a body wide immune response.
What is the name for immunity generated by innoculation subcutaneously or intramuscularly?
Systemic immunity.
What is the name for immunity generated by innoculation intranasally or orally?
Mucosal immunity.
