Module 12 Flashcards
Who discovered cowpox vaccinia
edward jenner
neutralization
pre existing antibodies can prevent secondary infection
what is the exception to neutralization
HIV in which antibodies are produced but fail to neutralize the virus
live attenuated vaccines are more potent than killed vaccines T or F
T
why do live attenuated vaccines produce a better immune response than killed vaccines
live attenutated vaccines elicit increased activation of CD4 t cells and cytotoxic CD8 t cells
what do cd4 t cells do
help b cells produce antibodies to protect against viral re infection
what do cytotoxic t cells do
eliminate the virus itself and provide protective memory
do killed viruses produce proteins in the cytosol
no
can killed viruses produce peptides to be presented on class 1 mhc
no
attenuated viral vaccines are used for what diseases
measles mumps rubella and varicella
viruses are attenuated how
by growth on nonhuman cells
what is the problem with attenuation
a pathogenic strain of the virus can re emerge after attenuation due to additional mutations
what is another way to produce attenuated vaccines
recombinant DNA technology
BCG vaccine can prevent what
tuberculosis in children
what cant BCG vaccine prevent
adult pulmonary disease
where did BCG come from
an attenuated strain of mycobacterium bovis
what type of vaccines can activate T and B cells
conjugate vaccines
haemophilus influenza b is what type of vaccine
conjugate vaccine
what makes up the haemophilus influenza type b vaccine
a conjugate of a bacterial polysaccharide that stimulates b cells and a tetanus toxoid that promotes helper t cells
children under the age of 2 cannot get what type of vaccine
t independt response vaccines
what kind of vaccine is used for children under the age of 2
conjugate vaccines
t cell peptide epitopes can stimulate protective immunity t or f
t
what are the issues with peptide based vaccines
may not bind all MHC types, peptide could load on non antigen presenting cells, failure to enter class 1 mhc processinf for presentation to cd8 t cells
what do adjuvants do to vaccines
increase the immunogenicity
compounds that mimic how infections normally activate immunity are called
adjuvants
alum
used in tetanus toxoid vaccines
what does alum stimulate
the inflammasome
what could replace the process of generating attenuated viruses for vaccines
what is ebola virus
filamentous negative stranded RNA virus
the most promising vaccines for ebola involve
over expression of glycoprotein and or nucleoprotein using replication deficient recombinant adenoviruses or plasma vectors that transduce targets to make large amounts of the ebola antigens that enter the general circulation
vaccines composed of intact nonpathogenic microbes are made by
attenuating virulence or killing the microbe
attenuated microbial vaccines can
elicit innate and adaptive immune responses, humoral and cell mediated
attenuated or killed bacterial vaccines usually
produce short term and limited protection
live attenuated viral vaccines are
more effective and vaccination in childhood produces lufe long protection
what are examples of live attenuated viral vaccines
polio, measles, yellow fever
vaccines made of antigens purified from microbes or inactivated toxins and are administered with an adjuvant
subunit vaccines
subunit vaccines
vaccines made of antigens purified from microbes or inactivated toxins and are administered with an adjuvant
purified antigen vaccines are effective for
prevention of diseases caused by bacterial toxins
toxoids induce
strong antibody responces
examples of subunit vaccines
diptheria and tetanus toxoids
vaccines composed of bacterial polysaccharides produce what type of t cell antigens
t cell independent antigens
t cell independent antigens produce what type of immune response
weak
conjugating t cell independent antigens to protein does what
enables weak antigens to mount strong b and t cell reponsses
conjugate vaccines
conjugating proteins to bacterial polysaccharides
vaccines made by recombinat DNA tech are in use for what
HSV, human papilloma and rotavirus
how can novel vaccines be made
by introducing genes encoding viral antigens into a noncyropathic virus
what is the advantage of live viral vaccines
the live virus will induce a strong and complete immune response which promotes innate and adaptive immune mechansims
what is the problem with live viral vaccines
the viruses could infect host cells producing foreign viral antigens that stimualte ctls to kill infected cells
DNA vaccines
inoculating with a plasmid containing cDNA for a protein antigen
DNA vaccines produce
long lasting adaptive immunity, humoral and cell mediated
apcs are transfected with the plasmid, the cdna is expressed as an immunogenic protein that elicites immune response
DNA vaccines
why can dna vaccines induce potent ctl responses
because antigenic proteins are made in the cytosol
bacterial plasmids are
recognized by tlr and activate innate immunity
protective immunity
conferred by transferring specific antibodies to rapidly treat potentially fatal diseases caused by toxins or from rabies or hepatitis
passive immunity
short lived and does not induce memory so the individual is not protected from subsequent exposure to toxins or microbes
what is needed for b cell response to protein antigens
peptide specific helper t cells
microbial constituents
bacterial polysaccharides can induce antibody production in the absence of t cells
t independent antigens
antibodies that can induce antibody production in the absence of t cells
purified subunit vaccines
are composed of antigens purified from microbes or inactivated toxins like tetanus
what is the best route for effective vaccination
the point of entry of the infectious agent
why do some diseases lack effective vaccines
natural infection does not generate protective immunity, antibodies produced are insufficient to prevent reinfection and eliminate the pathogen, cell mediated immune responses limit pathogens but do not eliminate them, there are technical and economic problems that prevent widespread use of vaccines
synthetic viral subunit vaccines
are composed of virall proteins synthesized from recombinat genes
what was the first syntehtic subunit viral vaccine
hepatits b
live attenuated oral virus vaccines
causes good induction of mucosal immunity but risk developing a viral disease especially in immunocompromised hosts
what is the advantage of using live attenuated organisms as vacccines
processed by cytosolic antigen processing pathway and presented on class 1 mhc
when an antigen has low immunogenicity which of the following can be added to a vaccine mixture containing the antigen to boost the immune response
adjuvant
what is meant by herd immunity
that the majority of a population is immune to a particular pathogen reducing the probability that an infected person comes into contact with a susceptible individual
