module 02 section 03 (vaccine efficacy) Flashcards
what is the only disease that has been officially eradicated?
small pox
define “pandemic”
the worldwide spread of a new disease
what are the two key viral glycoproteins of the influenza virus?
(1) hemagglutinin (HA)
2) neuraminidase (NA
what is the role of hemagglutinin?
allows attachment of the virus to cells
what is the role of neuraminidase?
helps new virus escape from host cells
describe the genome of influenza
has 8 segments of ssRNA, each associated with proteins and an RNA polymerase
what is the principle means of reducing/counteracting the influenza mortality and morbidity burden in our community?
the influenza vaccine (flu shot)
what is unique about the influenza vaccine?
the virus is always evolving/changing so the vaccine requires continuous monitoring and reformation
what is the valency of the flu shot and what is it composed of?
tri- or quadrivalent vaccine composed of the most prevalent influenza types from the previous year
what are the two principal reasons to get the flu shot?
(1) immune response dampens over time
2) influenza mutates (antigenic shift and drift
what does shift/drift of the influenza virus allow for?
allows the virus to evade pre-existing immunity of the host
can the influenza virus create an epidemic each year? why or why not?
yes - bc constantly changes
when does antigenic shift occur?
occurs when different types of influenza virus infect a single cell
explain what antigenic shift is
new combinations of HA/NA proteins can be created when RNA genome segments are swapped between various types of influenza viruses in a single infected cell
what type of resistance do people tend to have towards these new combinations (as a result of antigenic shift)?
due to rapid/drastic changes people tend to have little to no resistance against the new combination
when does antigenic drift occur?
occurs when the virus accumulates various point mutations in its genome
explain how antigenic drift can occur
the adaptive immune system does not recognize the newly mutated HA/NA proteins and the virus can escape the immune response
antigenic drift is responsible for what?
the changing flu vaccine formulation every year
what type of antibody typically blocks the influenza virus? explain how these function
- neutralizing antibodies - block to the influenza cell receptors that allow the virus to bind to host cells - blocking its propogation into host cells
- these are the antibodies that are blocked by shift
when travelling to Cuba, it is recommended that you get vaccinated against _______?
hepatitis A and B
when travelling to Brazil, it is recommended that you get vaccinated against _______?
yellow fever
when travelling to Argentina, it is recommended that you get vaccinated against _______?
hepatitis A
when travelling to Niger, it is recommended that you get vaccinated against _______?
yellow fever
when travelling to the Democratic Republic of Congo, it is recommended that you get vaccinated against _______?
polio
when travelling to Israel, it is recommended that you get vaccinated against _______?
hepatitis A
when travelling to Syria, it is recommended that you get vaccinated against _______?
polio
when travelling to Mongolia, it is recommended that you get vaccinated against _______?
typhoid
when travelling to Indonesia, it is recommended that you get vaccinated against _______?
japanese encephalitis
what are exceptions to getting common vaccines? (7)
age, pregnant, weak immune system, have medications/cancer treatment, removed thymus, currently sick, potential allergy to the vaccine contents, etc.
overview: what is the basic principle behind vaccines?
vaccines produce protections against infections by stimulating the development of long-lived effector cells and memory cells
(overview)
antigens may be: (type of substance?)
sugars, lipids, carbs, proteins, nucelic acids
what is the fundamental reason for vaccines?
herd immunity
