Immunology Lecture 8_Vaccines Flashcards
Describe what Ro means
Ro is the number of people an infected individule will infect in a nonvaccinated population
Define herd immunity
Herd immunity is the idea that if a sufficent percentage of a population is vaccinated, an infection cannot spread because there are not enough potential carriers. This protects people who cannot be vaccinated
Define duration of immunity
Immunity does not last forever. Some vaccines require booster shots. Some types of vaccines are more effective than other
How is threshold for herd immunity calculated
(1-(1/Ro))*100 this is the precentage of your population that needs to be vaccinated to achive herd immunity
Describe passive immunity verse Active Immunity
Passive immunity is when antibodies of one individule are give to another. This includes the anti bodies of a mother passed through the plecenta to a fetus and through breast milk to a baby
Active immunity is when an individule is personally producing antibodies against an antigen from memory B cells. Active immunity is more long lasting than passive immunity
What is a live attenuated vaccine
A live attenuated vaccine is a vaccine that contains a virus that has lost virulence. It is rare but the virus can regain virulence. This ellicites some of the strongest immunity of all vaccination types
What is an inactivated vaccine
It is a vaccine that contains a pathogen that has been killed by heat, chemicals, or radiation. It does not provide as robust an immune response as live attenuated vaccines but is generally safe because the dead pathogen cannot regain virulence. Some pathogens can be heard to kill, like staph a., and so incomplete inactivation is possible
What is a viral vector vaccine
A non infectioues viral vector is used to carry the genes for an epitope of a different pathogen thus granting immunity against that pathogen. One limitation of viral vector vaccines is that the body will develope an immunity against the vector. This means that a particular vector can only be used once.
Define Toxoid vaccines
Toxid vaccines are a class of vaccine where a toxin is inactivated and then injected so the body can establish an immunity. These vaccines typically only have a duration of about 1 year
Define Adjuvants
Adjuvant are additives added to vaccines to boost their effectiveness. Unfortunetly, safety is inversly proportional to efficacy
Describe Alum
Alum is a type of aduvant. It is a mineral salt that promotes aggrigation of the antigen. This allows for stronger immune response because the pathogen is isolated. This is what is responsible for localized sorness after the administration of some vaccines.
