Vaccines for Infectious Diseases Flashcards
What are the characterizations of passive immunization?
- temporary
- prevent dieases AFTER exposure
- protect immunosuppressed patients
- block action of bacterial toxins
What are examples of passive immunization?
- snake bite anti-venom
- passive transfer of Ig from mother to child
- breast feeding
What are the characterizations of active immunization?
- delayed immunity but more permanent
- prevent disease BEFORE exposure
What are examples of active immunization?
- vaccines
- natural exposure to Ags from pathogens
What is the effectiveness of vaccines?
- evoke protective levels of immunity
- induce immune memory
What is the availability of vaccines?
readily cultured in bulk
What is the stability of vaccines?
stable under extreme climatic conditions
What are the types of vaccines?
- inactivated/killed
- live/attenuated
- taxoid
- subunit
- recombinant protein
- conjugate polysacc.
- mRNA
What are the characteristics of inactivated/killed vaccines?
- inactivation of pathogen by chemical means to generate preparation that induces an immune response but DOES NOT replicate in host
- safe
What are examples of inactivated/killed vaccines?
- salk polio
- influenza
- hepatitis A
- cholera
What are the characteristics of live/attenuated vaccines?
- “weakened” preparation
- attenuated by environmental conditions or genetic engineering
- not as safe due to potential for reversion of attenuation
- generates humoral & cell mediated immunity
What are examples of live/attenuated vaccines?
- varicella zoster
- measles
- mumps
- rubella
- oral Sabin polio
- anthrax
What are toxoid vaccines?
- toxins treated with formalin or genetically modified to generate toxoids that are immunogenic NOT TOXIC
- inactivated
- relates to bacterial toxins
- type of subunit vaccine
What are examples of toxoid vaccines?
tetanus and diptheria
What are subunit vaccines?
- isolate subunit from organism to be used as vaccine
- purified from organism or generated by recombinant DNA tech.
What is an example of a subunit vaccine?
acellular pertussis (whooping cough) -> results in strong Ab and Th1 response
What are recombinant protein vaccines?
- generate protein from organism through recombinant DNA tech.
- only produces Abs
- type of subunit vaccine
What is an example of a recombinant protein vaccine?
hepatitis B surface Ag made in yeast
What vaccines are handled as exogenous Ags?
- recombinant
- toxoid
- inactivated/killed
- subunit
- conjugate polysaccharide
*live/attenuated
What vaccine is handled as an endogenous Ag?
live/attenuated
What are the characteristics of the mRNA vaccine?
- very short half-life
1. codes for protein Ag
2. complexed with lipid nanoparticle carrier
3. lipid fuses with membrane
4. mRNA translated inside Ag
5. Ag presented to T/B cells
What are examples of mRNA vaccines?
- spike proteins -> T cell activation & Ab production
- COVID vaccine
What is a conjugate polysaccharide vaccine?
- protein conjugated with polysaccharide capsules to generate T helper cell responses to the polysaccharide capsules
- only produces Abs
What are examples of a conjugate polysaccharide vaccine?
- Hib
- pneumococcal
- meningococcal
What are adjuvants?
non-specific immune enhancers that functions partially through stimulation of innate immune system
What is the depot effect within adjuvants?
- slow release of Ag
- production of cytokines
- particle increase
- inflammatory response
- required with non-live vaccines
What are the types of adjuvants?
- inorganic salts
- oils
- bacterial porducts
- aluminim OH
What determines the course of tuberculosis?
immune response
What causes tuberculosis to become progressive?
if Th2 predominates
If there is a Th1 response with tuberculosis, what happens?
protection
What are the characteristics of tuberculosis?
- slow developing
- caused by Mycobacterium tuberculosis
- symptoms: fever, cough, bloody sputum, weight loss, losse of energy, progressive lung damage
How does the BCG vaccine work for tuberculosis?
- type of live attenuated vaccine
- culture of M. bovis
- immunity in vaccinated animals cannot be transferred with serum
- protective immunity can be transferred with CD4 cells
- T cell response in vaccinated animals is faster than in naive animals
What are the limits of the BCG vaccine?
- initial deaths in kids
- different strains
- adverse reactions: localized fatal desseminated BCG infection
- varied efficacy
- compromises tuberulin skin test
- NOT IN US
What does a positive BCG vaccine result in?
a positive TB skin test
What is corynebacterium diphtheriae?
- produces diphtheria toxins
- gram +, club-shaped bacillus
- diphtheria exotoxin inhibits protein synthesis in host
What is a diphtheria toxoid?
- treated with formalin
- absorbed onto adjuvant
- combined into DTaP/DTP (vaccine)
- minimum level of antitoxin always obtained after vaccination
What are the characteristics of bordetella pertusis?
- gram -, aerobic
- coccobacillus, non-motile
- delicate, slow grower
- very infectious
- causes whooping cough in kids
