20 - Immunizations Flashcards
Which Vaccines have
BOTH
Live & Inactivated Agents
Influenza
POLIOmyelitis
Typhoid
Measles
Which LIVE VACCINE requires a booster?
MMR
Needs a booster
Live Attenuated Vaccines
can replicate inside recipient –> logarithmic growth of Ag’s
typically LIFELONG immunity
- *Which INACTIVATED VACCINES**
- *do NOT require REPEATED VAX + BOOSTERS**?
HEP B + *Inactivated* POLIO
In INACTIVATED VACCINES:
such as Tdap / Rabies / Typhoid
they require repeated vaccination + boosters to maintain HIGH AB levels
Determinants of IMMUNOGENECITY
In VACCINES
Chemical + Physical States
of the Ag
- *Characteristics of INDIVIDUAL**
- *Genetics / Physical Condition**
HOW antigen is PRESENTED
ROUTE / DOSE
TIMING of dose / ADJUVANTS
T-Lymphocyte-INdependent Immune Response
Determinants of ImmunoGenicity
no immunologic memory
can NOT be boosted with REPEAT injections
- POOR immunogenicity in:*
- *Infants / Young Children**
Can be OVERCOME by
- *LINKAGE to CARRIER PROTEIN**
- *Conjugated Hib / pneumococcal / meningocccal**
T-Lymphocyte-Dependent Immune Response
Determinants of ImmunoGenicity
IDEAL RESPONSE
Induces:
Immunologic MEMORY
Boosts effects with REPEAT ADMIN
Provides immunogenicity to:
ALL AGE GROUPS
What determines the BREADTH of an immune response?
Determinants of Immunogenicity
ROUTE of administration
IM & SC routes confer:
a predominantly systemic IgG response
- *Oral** or Nasal produces:
- *local IgA** & some systemic IgG
What determines the EXTENT of an immune response?
Determinants of Immunogenicity
AMOUNT of ANTIGEN delivered
Dose-Response relationship
that reaches a certain plateau
Temporal Course of an IMMUNE RESPONSE
Initial Response
Protective Immune Response ~2 weeks
Circulating Antibodies appear in 7-10 days
low affinity IgM FIRST (imMediate) –> HIGH affinity IgG
IgG AB’s –> neutralize / precipitate / fix complement
- *Titer PEAK = 2-6 weeks**
- then begins to decrease*
Temporal Course of an IMMUNE RESPONSE
SECONDARY Response
“Booster”
4-5 days
vs 7-10 days for first response
HEIGHTENED Humoral or CELL-Mediated RESPONSE
What is the ASSAY OF CHOICE
when measuring VAX Immune Response?
- *OPSONOPHAGOCYTIC ACTIVITY**
- ideally would be measuring CELL-MEDIATED immunity*
Appearance & Concentration of Serum Antibodies
Measures only the HUMORAL response = B-cell
failure can occur due to loss of circulation AB’s over time
absence of AB does NOT mean lack of protection
but also mere presence of AB does NOT mean immunity
need a SPECIFIC CONCENTRATION
Vaccine Development
Attenuation = reduced effect / virulence
achieved by serial passage in tissue celll culture lines
but still maintaining immunogenecity
Inactivated Vaccines
developed in bacteria following
concentration / purification / inactivation
NEWER vaccines are developed by:
Recombinant techniques / LIVE vectors / MICROencapsulation into polymers (sustained release)
Where should we look for
IMMUNIZATION RECOMMENDATIONS?
- *ACIP**
- *A**dvisory Committee on Immunization Practices
updated ANNUALLY
Decition to admin the vacicine involves:
Risk of Disease
+
Benefit & Risk of Vaccine
Benefit + Risk Balance may change over time
need to continually assess
Inactivated Flu Vaccine
Production / Content
Primarily manufactured IN EGGS
cell culture vaccine in marine darby CANINE KIDNEY cells (still egg)
Only NON-EGG form = recombinant INSECT CELL LINE
Composed of: inactivated disrupted/split flu viruses
or of purified SURFACE antigens
A Viruses H1N1 + H3N2 & 1 B strain
quadrivalent = 2 B strains, but EQUALLY EFFECTIVE
ANTIGEN DRIFT
is why we require annual changes in vaccine components
Inactivated Flu Vaccine
Administration / Indications
for INACTIVATED VACCINES =
BENEFIT ALWAYS OUTWEIGHS THE RISK
IntraMuscularly
High Dose = 4x Antigenic Content
given annually for:
EVERYONE > 6 months Old