Lecture 5 - Vaccines Flashcards
what is the most common type of antibody?
IgG
why is IgG the most common antibody?
IgG is the most stable and simple structure
2 measures of binding strength?
- affinity
- avidity
what is affinity?
measure of binding strength at a single binding site
what is avidity?
measure of total binding strength
affinity and avidity of IgM vs IgG
IgM has higher avidity but lower affinity
what is Ig class switching?
factors in B cell environment (like cytokines) allow Ig to switch btwn diff classes
2 reasons why we don’t have vaccines for everything?
- money
- some viruses/pathogens can evade immune system
why is there no HIV vaccine?
HIV mutates too much
what is an adjuvant?
added in vaccines to improve immune response in ppl receiving the vaccine
causes more local reactions (pain, swelling, redness)
type of adjuvant?
aluminum salt
why do we get boosters?
to induce increased secondary antibody response
when is the secondary response worse than the primary?
Dengue virus
4 types of vaccines?
- attenuated/weakened virus
- inactivated virus
- inactivate part of pathogen
- RNA/DNA
describe Streptococcus pneumoniae in healthy carriers
asymptomatically sits in respiratory tract, sinuses, and nasal cavity
what does streptococcus pneumoniae cause?
community-acquired pneumonia
describe the pneumococcal vaccine
uses purified polysaccharide with immunogenic adjuvant to be a CONJUGATED VACCINE
humoral vs cell-mediated immunity
humoral = antibodies for extracellular pathogens
cell-mediated = immune cells attack infected cells, cancers, transplant tissue
what is mucosal immunity?
immunity at the site of infection
what is the BCG vaccine for?
TB
how was the BCG vaccine made?
used virulent strain of Mycobacterium bovis from cow with tuberculosis mastitis
other effects of the BCG vaccine?
can help protect from other infections
why does the BCG vaccine help with other infections?
goes into bone marrow to induce trained immunity!
what is trained immunity?
epigenetic modifications of stem cells so innate immune cells become better trained to fight infection
