Mar28 M2-Vaccines 1 Flashcards
how idea of vaccines started
noticed people injected with cowpox were immune against small pox (which was much worse)
how do we choose what to vaccinate for + 2 examples
things for which we have no reliable treatment
- diphtheria = 40% fatality rate
- polio = 10% paralysis rate
things we vaccinate for and that are lethal
polio, diphtheria, tetanus, pertussis, chicken pox
small pox charact
- now eradicated (bc is a disease of humans, if has animal reservoir, much harder)
- infection rate 100% (sick person infects everyone in the room)
3 things vaccines do
- stimulate immunity (get appropriate protection): is why we repeat the flu shot every year
- stimulate memory
- herd immunity
herd immunity def
low number of susceptible individuals + lot of vaccinated people around them = susceptible people are protected bc pathogen doesn’t circulate much
why should a parent care about herd immunity (and vaccinating their child to protect others)
- their child themself is susceptible (along with elderly and immunocompromised)
- if unvaccinated, may bring back disease from daycare and give it to younger sibling who can’t get vaccinated
killed or particulate vaccine def
mushed up the microbe and injected it. no chance of giving the disease
particulate vaccines used in what diseases
diphtheria and tetanus because are toxemias. the toxins generated by these bacteria are inactivated and given as a vaccine
problem with diphtheria vaccine (not really a problem)
- diphtheria bacteria is still circulating
- you get the bacteria, sore throat and cough
- you don’t get diphtheria as a disease (don’t get the toxemia)
type of vaccines used for viruses and why
- live viral vaccine
- need live virus to infect cells and then only this will stimulate CD8+ cells
example of live viral vaccine
polio vaccine
goal of a conjugated vaccine
- conjugate piece of a pathogen that usually has a polysaccharide enveloppe to a piece of peptide from diphtheria or tetanus (that will be in vaccine anws)
- T cells can be activated because recognize a peptide this way
- activated T cell can tell the B cells that can recognize the enveloppe to make much more Abs (osponization, complement, cell mediated cytotoxicity) + memory B cells
why need conjugated vaccine
- without it, B cell acts in a manner called T INDEPENDENT RESPONSE. sees polysaccharide on the fat enveloppe and make Abs but NO MEMORY RESPONSE
- people below age 2 and over 70 don’t do a good immune response to these pathogens
what pathogens do we do a conjugated vaccine for
pneumococcus and meningococcus (deadly pathogens) that have a fat envelope covered with polysaccharides
