Immunization and Antibiotics Flashcards
what is immunologic specificity?
the degree to which an antibody recognizes an antigen
what is variolation?
ground up scabs of people infected with small pox and shoot the powder up their nose; 2% chance of death
what virus caused small pox?
VARIOLA
what is cross protection?
milk maids who got cow pox had immunity to small pox
produce the same major antigens
describe vaccines that kill the whole organism
ex. hep A vaccine, SALK VACCINE
pros: easy to produce, many antigens present for a robust response
cons: hard to inactivate
what was the cutter incident?
some batches of the SALK polio vaccine contained the live virus, caused 250 cases of polio
what is live, attenuated vaccines?
ex. BCG (TB vaccine), SABIN polio vaccine
organisms have been weakened in some way
pros: pathogen presented to the right part of the body, allows for a robust response
cons: difficult to produce, cannot give to immunocompromised, cold chain distribution needed
what are subunit vaccines?
ex. streptococcus pneumoniae capsular antigen, viral capsids from HPV, TOXOID VACCINES (tetanus)
selected, purified antigenic components of pathogens
pros: easy to produce, no chance of infection
cons: hard to find protective agent
what are nucleic acid vaccines?
Ex. COVID vaccine
contain mRNA that codes for a specific antigen, wrapped in a lipid layer and injected
mRNA has a short life, rapidly dealt with by NK cells
benefits: easy to manufacture, quick to get to market, NO CHANCE OF INFECTION
cons: cold chain distribution, hesitancy
why are booster shots needed?
first dose causes synthesis of IgM, then IgG
booster shot results in a rapid response, since memory B cells formed during first response
booster ensures sufficient antibodies with sufficient reactivity
describe antigenic changes
some pathogens can change their shape or antibodies
ex. COVID, influenza
describe waning memory
memory T-cells and B-cells do not have an indefinite life span
can lose specificity when they replicate
ex. tetanus shot every 10 years
what are the best type of vaccines?
LIVE ATTENUATED
activates the immune system properly, to the right part of the body, prevents a mild form of the infection being passed onto others
what is herd immunity?
for diseases spread person to person, vaccinating a large part of the population interrupts transmission of the disease
important for immunocompromised individuals
what is vaccine hesitancy?
problematic atm due to social media and a lack of fact checking
people believed Jenner’s vaccine would turn them into cows
measles outbreak in New Brunswick
who actually discovered antibiotics first?
ernst dechesne discovered antibiotic properties of penicillin moulds
who stabilized penicillin?
HOWARD FLOREY and ERNST CHAIN
won nobel prize with femming
who was GERHARD DOMAGK?
german physician, daughter got infection from a pinprick
injected her with a dye called PRONTOSIL, cured her
how does PRONTOSIL work?
SULFA DRUGS
prontosil is metabolized to sulfanilmide in the body, inhibits the enzyme that makes folic acid, inturrupting bacterial metabolism
what was WAKSMAN’S contribution?
screened soil bacteria for antimicrobial activity
discovered STREPTOMYCIN
what is SELECTIVE TOXICITY?
drug is toxic against one part of the pathogen and leaves host alone
ex. targets peptidoglycan, ribosomes
how do bacteriostatic drugs work?
prevent growth, but DO NOT KILL it
suspends growth and buys time for immune system to kick in and kill it
what does antibiotic effectiveness depend on?
organism being treated
attainable tissue levels of the drug
route of administration
how can we measure inhibitory concentration?
serial dilutions of a 96-well plate
E-strips
kirby-bauer disk diffusion
ALL TAKE TIME
