Vaccines Flashcards
What keeps unvaccinated individuals safe?
Herd Immunity
Explain R0 (R naught)
It is the average number of secondary cases produced by one primary case in a susceptible population.
Greater than 1 is more than one secondary infection per primary case. Increase Disease.
Lower than 1 is a decrease in the disease.
Exactly one is a stable disease.
What is the formula for the threshold of people that need to be vaccinated to keep herd immunity?
1-1/R0
Gives percentage of people that need to be vaccinated. The threshold. Example threshold for Malaria R0=86 is 99%
What is passive immunity? What are examples
It is immunity taken from the serum of one individual that has the antibodies of a disease that is then given to someone who has the disease or may have the disease.
Is short lived
Breast milk with IgA, Placental immunity IgG
Tetanus, anti venom, rabies
What is active immunity?
It is the activation of B cells that remember a pathogen or infection.
What is the key of live-attenuated viruses?
They have a loss of virulence (sending them on vacation)
What is the key of inactivated vaccines
Loss of infectivity
What are the cons of Inactivated Vaccines?
They are not as effective as live.
DIVA problem: Distinguishing infected from Vaccinated. (Did the immunity come from a previous infection or from the vaccine?)
What are two kinds of genetically engineered vaccines?
Recombinant DNA
Virus like Particles (expensive) HPV*
Adjuvants are what?
Alum: promotes phagocytosis and influences the inflammasome
Squalene
How much more vaccine does a larger individual need in response to size?
No difference
Explain the Dengue Fever Vaccine
Those exposed the first time to dengue fever vaccine had worse effects than those who had been exposed before.
