microbio lecture 15 Flashcards
1
Q
Immunization
A
is process of inducing immunity
2
Q
what has probably had greatest impact on human health of any other medical procedure?
A
immunization
3
Q
knowledge is _____________ with respect to fighting disease
A
power
4
Q
useful applications of ___________ ________ in diagnostic tests
A
immunological reactions
5
Q
today __#__ diseases around the globe can be prevented by vaccination
A
30
6
Q
immune wars -> pathogens fight back ->
A
return of humans (knowledge is power)
7
Q
Naturally acquired immunity
A
gained through normal events, such as
illness
8
Q
Artificially acquired immunity
A
gained through immunization
9
Q
Active immunity
A
results from exposure to antigen
10
Q
in active immunity, lymphocytes are
A
activated, memory cells provide long-lasting protection
11
Q
active immunity is natural by
A
infection, passive through vaccination
12
Q
passive immunity
A
results from addition of other’s antibodies
13
Q
passive immunity is temporary
A
protection, no memory cells formed
14
Q
natural passive immunity
A
- During pregnancy, mother’s IgG antibodies cross placenta
- Breast milk contains secretory IgA
15
Q
artificial passive immunity
A
Injection of antiserum containing antibodies
16
Q
injecting antiserum can prevent
A
disease before or after likely exposure, limit duration of certain diseases, and block action of microbial toxins
17
Q
antitoxin is
A
antiserum that protects against a toxin
18
Q
what is antiserum (not in slides)
A
preparation of serum that contains protective antibodies
19
Q
Hyperimmune globulin
A
(antibodies to specific disease)
20
Q
Immune globulin
A
(IgG fraction from many donors; variety of antibodies)
21
Q
Monoclonal antibody
A
therapeutics
22
Q
natural active immunity
A
Immunity that results from an
immune response in an individual
after exposure to an infectious agent.
23
Q
Artificial Active Immunity
A
Immunity that results from an
immune response in an individual
after vaccination.
24
Q
Natural Passive Immunity
A
mmunity that results when
antibodies from a woman are
transferred to her developing fetus
during pregnancy or to an infant
during breast feeding.
25
Artificial Passive Immunity
Immunity that results when
antibodies contained in the serum
of other people or animals are
injected into an individual.
26
Vaccine
preparation of pathogen or its products used to
induce active immunity
27
vaccine protects
individual and prevents spread in population
28
herd immunity
develops when critical portion of population is immune to disease
29
infectious agent unable to spread due to insufficient susceptible hosts
(requiring, usually not less than 75% of a population)
30
vaccine is responsible for dramatic declines in
childhood disease-- diseases sometimes reappear and spread as result of failure to vaccinate children
31
effective vaccine should be safe, with few side effects. some characteristics are
* Give long lasting protection
* Ideally low in cost, stable, easy to administer
32
two general categories of classical vaccines
live attenuated vaccine; inactivated vaccine
33
Live Attenuated Vaccine (agent can replicate)
stronger immune response, but
may cause disease
34
Inactivated vaccine (agent cannot replicate)
weaker immune response, but
cannot cause infections
35
attenuated vaccines
Attenuated bacteria
Injection, oral, or nasal Injection Route
No Need for adjuvant
Antibody response (memory): IgG; secretory IgA if administered orally or nasally IgG
Good Cell-mediated response
Longer Relative duration of protection
Usually One or 2 doses
Very Low Risk of mutation to virulence
Significant Risk to immunocompromised recipient
Poor Stability in warm temperatures
36
Inactivated vaccines
Inactivated whole agents, toxoids, subunits, Virus-like particles, polysaccharides, conjugates
Injection Route
Need for adjuvant
Antibody response (memory): IgG
Poor Cell-mediated response
Shorter Relative duration of protection
Multiple doses
Absent Risk of mutation to virulence
Absent Risk to immunocompromised recipient
Good Stability in warm temperatures
37
Attenuated vaccine
weakened form of pathogen
38
attenuated vaccines grown under conditions that
foster mutations, or genetically manipulated to replace genes – both lower pathogenicity
39
advantages of attenuated vaccine
* Single dose usually induces long-lasting immunity due to microbe multiplying in body
* Can inadvertently immunize others by spreading
40
disadvantages of attenuated vaccine
* Can sometimes cause disease in immunosuppressed individuals
* Can occasionally revert or mutate, become pathogenic
* Generally not recommended for pregnant women
* Usually require refrigeration
41
examples of attenuated vaccines
measles, mumps, rubella, chickenpox, yellow fever, rotavirus
42
Inactivated vaccine
unable to replicate, but still immunogenic
43
advantages of inactivated vaccine
cannot cause infections or revert to pathogenic forms
44
disadvantages of inactivated vaccine
no replication, so no amplification; several booster doses usually needed
45
inactivated often has an adjuvant,
which enhances immune response to antigens
46
some adjuvants provide
signals to dendritic cells through toll-like receptors activation
47
some adjuvants hold ________ and release it slowly over time
antigen
48
adjuvant examples
Aluminum salts; derivatives of Lipid-A; Cytosine-Phospho-Guanine (a DNA mimic)
49
some adjuvants trigger _________ __________
inflammatory response
50
adjuvant is an ingredient used in some vaccines that helps create
a stronger immune response in people receiving the vaccine. THEY cause more local reactions (such as redness, swelling, and pain at the injection site) and more systemic reactions (such as fever, chills and body aches) than vaccines not containing adjuvants.
51
Inactivated whole agent vaccines
contain killed microorganisms or
inactivated viruses
52
inactivated whole agent vaccines treated with __________ that does not significantly change surface epitopes
formalin or other chemical
53
inactivated whole agent vaccines can include
influenza, rabies, hepatitis A
54
toxoid vaccines
toxins treated to destroy toxic part, retain antigenic epitopes
55
toxoid vaccines include
diphtheria and tetanus
56
subunit vaccines consist of
key protein antigens or antigenic fragments from pathogen
57
subunit vaccines avoid
cell parts that may cause side effect
58
what is an example of subunit vaccine?
acellular pertussis (aP) vaccine
59
recombinant subunit vaccine
subunit vaccines produced using
genetically engineered microorganisms
60
hepatitis b virus is recombinant example, where
yeast cells produce part of viral protein coat
61
VLP (virus-like particle) vaccines
empty capsids produced by genetically engineered organisms
62
example of VLP
human papillomavirus
63
Polysaccharide vaccines
contain polysaccharides from capsules
64
polysaccharide vaccines not effective in young children and are
t-independent antigens which elicit poor response
65
example of polysaccharide vaccine
pneumococcal vaccine for adults
66
conjugate vaccines
polysaccharides linked to proteins
67
the conjugate vaccines convert ____________ into t-dependent antigents
polysaccharides
68
conjugate vaccine example
Haemophilus influenzae type b (Hib) has nearly eliminated
Hib meningitis in children; Streptococcus pneumoniae vaccine promises to
do the same for a variety of infections
69
Nucleic acid-based vaccines
Segments of naked DNA or RNA from infectious agent
70
nucleic acid based vaccines induce
immune respone (covid-19)
71
some cells express genes for _____ ______ after injection (nucleic acid-based vaccines)
short period
72
vaccines benefits greatly
outweigh very slight risk
73
child with measles chance of serious brain inflammation
1:2000
74
child change of brain inflammation from vaccine
1:1000000
75
prior to vaccinations, there were
numerous deaths and disabilities
76
many with vaccines can still
become ill or die from preventable diseases
77
some parents refuse to vaccinate children because they
fear harm
78
however, no evidence of link between
vaccines and autism
79
vaccines have become victims of
their own success because people don't see seriousness of disease
80
reports of adverse effects of vaccine lead some to
falsely believe that the risk of vaccination is greater than the risk of disease
81
vaccination dramatically reduces
incidence of diseases
82
drops in immunization rates lead to
disease outbreaks
83
Since the beginning of the COVID19 pandemic,
over 750 million confirmed cases worldwide have
been infected resulting in >7 million deaths
84
In the US, 100 million confirmed
infections and >1.1 million deaths (~ 3 year total)
85
When faced with a deadly, global pandemic, naturally,
a vaccine is desirable to stop it.
86
challenges of pandemic
* This is a new pathogen that we know little about.
* People are dying! Needs to be quick!
* We can guess that the spike protein might be an appropriate target but we are not sure.
* We will need to produce 3-5 billion doses in less than a year (350 million x 2 doses for US alone)
87
What is best approach for pandemic?
* Live attenuated vaccine is out because of time and number of doses needed
* Only practical approach is an mRNA vaccine and it just so happens to be the best approach!
* Modified booster with different reactivity can easily be made if virus mutations resist immunity
88
mRNA vaccine general strategy
target pathogen -> genome sequencing -> electronic transfer of sequence -> vaccine design ->pilot mRNA vaccine production and validation -> GMP manufacturing of mRNA vaccine -> vaccination
89
mRNA vaccine: injected mRNA stimulates
dendritic cell via RNA-specific Toll-like receptors to
secrete TNF-alpha and IL6
90
dendritic cells express
Co-stimulatory molecules to activate TH cells
91
then, TH cells expresses
“expressed” antigen in context of MHC Class I molecules
92
CD8+ T-cells react with cognate
Class I molecules, giving rise to Tc response
93
Dendritic cells can also express protein in context of
MHC Class II stimulaiton humoral rsponse
94
Some target protein escapes and binds
to B-Cell receptors
95
TH cells specific for target antigen stimulate B-Cells expressing target protein
in context of Class II molecule leads to
B-cell proliferation and differentiation
into plasma cells and production of antibody
96
The notion that natural immunity is better than than immunization is not
supported
by scientific data
97
Many diseases have high case mortality rates making
natural immunity impractical
98
Many disease (Syphilis, Gonorrhea, HPV, HIV, Cholera, Influenza, Typhoid fever, etc.)
do not illicit
sufficient natural immunity to prevent reinfection.
99
Natural immunity does not yield
life-long immunity except in rare cases
100
Immunization can prevent
many of the most deadly diseases that would otherwise yield high mortality or lasting debilitation
101
Preventable childhood diseases (rubella, measles, Hemophilus influenza, Pneumococcal pneumonia, chicken pox) are
not benign; complications are severe and
can be fatal
102
Vaccines to several important diseases still not available but
research continues with
some promising results (HIV, Malaria, Tuberculosis, Lyme Disease, West Nile, Zika
enchephalitis)
103
Though the history of vaccine use has some troubling examples
vaccines today are safe and safeguarded by procedures in place to protect the public.
104
Immunization is one of modern medicine’s
greatest success stories.
105
vaccine has probably had
greatest impact on human health of any other medical procedure
106
vaccine is example of how knowledge is
power with respect to fighting disease
107
today, 30 diseases around globe can be prevented by
vaccination
108
Though impossible to know for sure, the WHO conservatively estimates that________________ prevented each year.
2-3 million deaths
109
Immunizations impact on various cancers is
expanding rapidly
110
Hope for controlling multi-drug resistant bacterial infections by targeting
microbial resistance mechanisms
