Basic Principles of Vaccination Flashcards
Transfer of antibody produced by one human or an animal to another human
Temporary protection that wanes or disappears with time (usually within a few weeks or months)
Passive immunity
Passive immunity
sources of antibody
Transplacental transfer of maternal antibodies to infants
Blood products used for transfusion ((WB, RBC, Platelet, Convalescent Plasma)
Immune globulins derived from plasma of human donors or produced in animals (horse or equine-derived antibodies)
Natural passive immunity
Maternal antibody
Protection produced by stimulation of the person’s own immune system
Usually permanent -> lasts for many years or lifetime
Active immunity
Sources of active immunity
Natural infection with the disease-causing form of organism
Artificial sources: vaccination
Natural active immunity
Follows infection
Natural passive immunity
Transfer of antibodies across placenta
Artificial passive immunity
Injection of antibodies
Artificial active immunity
Exposure to antigen
Vaccination
Live attenuated vaccines from
Viral
Bacterial
Inactivated vaccines
Whole (virus or bacteria)
Fractional (protein based, polysaccharide)
Live microbe weakene by growth conditions in lab or less virulent relative
Live attenuated
Ex
MMR
BCG
BCG is made up of
M bovis
Microbe killed or inactivated by chemicals, heat or radiation
Inactivated (killed)
Ex
Influenza, IPV, rabies, inactivated Hep A
1-20 parts of microbe that best stimulate immune response
Subunit
Ex
Hep B, HPV, Influenza, acellular pertussis
Principles of Vaccination #1
The more similar a vaccine is to the disease-causing form of organism, the better the immune response to vaccine
Immune response and memory produced very similar to natural infection
Usually produce immunity with ONE DOSE
(except vaccine given orally rotavirus)
Applies to
Live attenuated
MMR, VZV, Rotavirus, Oral polio and JE vaccine
Bacterial: BCG, oral cholera
Live attenuated vaccines advantages
Mimic natural infection
Highly immunogenic
Provide long-lasting protection
Single dose often sufficient
Live attenuated vaccines disadvantages
Severe reactions possible - if they revert to virulence
Interference from circulating antibody
Fragile - must be stored and handled carefully (exposure to heat or light result in poor response)
Live attenuated vaccines in RHUs
BCG
OPV
MMR
Rota
JE
Varicella
Composed of killed microorganisms of inactivated components
Cannot replicate
Less interference from circulating antibody than live vaccine
Always require multiple doses (booster)
Immune response mostly HUMORAL
Antibody titer diminishes with time
May require periodic supplemental doses to “boost” antibody titers
Inactivated vaccines
Inactivated Whole Cell Vaccine
Viral: polio (IPV), hepatitis A, rabies, influenza
Bacterial: pertussis, typhoid, cholera
Inactivated Fractional Vaccine (protein based)
Subunit: hep B, influenza, acellular pertussis, HPV
Toxoid: diptheria, tetanus
Unique type of inactivated subunit vaccine composed of long chains of sugar molecules that make up the surface capsule of certain bacteria
Polysaccharide vaccines
Not immunogenic in children <2 years of age
No booster response
Antibody has less functional activity (mostly IgM)
Immunogenecity improved by
Pure polysaccharide vaccines
Conjugation
Vaccine is chemically combined with protein molecule
Conjugation
Antibody response of short duration, no memory and no affinity maturation
No response in young infants (<18 months)
Free polysaccharide vaccine
Antibody response of long duration, memory and affinity maturation
Protective response in young infants (>2 months)
Able to produce T cell response
Conjugated Polysaccharide vaccine
Inactivated fractional
Pure Polysaccharide Vaccines
Pneumococcal PPSV23
Meninggococcal
Samonella typhi (Vi)
Inactivated Fractional
Conjugated Polysaccharide Vaccines
Hib
Pneumococcal
Meningococcal
Inactivated vaccines advantages
Less reactogenic
No risk for causing disease
Less interference from circulating antibody
Often more stable to heat
Inactivated vaccine disadvantages
Often less effecfive than live-attenuated
Generally require 3-5 doses for long term protection
Antibody titer diminishes with time
Inactivated vaccines in RHUs
Hep 5
Pentavalent vaccine
IPV
Pneumococcal conjugate vaccine
Principle #2
All vaccines can be administered simultaneously at same visit but at different sites following the minimum age requirement.
EXCEPT
PCV 13 and MCV4-D (Menactra)
PCV13 and PPSV23
PCV13 and MCV4-D (Menactra) should be given separately by
4 weeks
PCV 13 and PPSV23 Polysaccharide should be given separately by
8 weeks
Simultaneous administration of vaccines:
Increases the probability that a child will be fully immunized at the appropriate age
If possible, use licensed combination vaccines to reduce the number of injections
Use separate syringes and separate sites
What is the best timing for non-simultaneous administration of different vaccines?
Principle #3
For two or more, live parenteral vaccines the minimum interval between doses is
4 weeks
All other vaccine combinations non-live parenteral could be given
simultaneously or at any interval between doses
Live oral vaccines like
OPV, Rota, Ty21a typhoid vaccine can be administered
simultaneously or at any interval before or after inactivated or live parenteral vaccine
What is the interval between antibody containing blood products and vaccines?
Principle #4
Inactivated vaccines generally are not affected by circulating antibody to the antigen
Inactivated vaccines can be administered
Before, after or at the same time as the antibody
Simultaneous administration of antibody (immune gobulin) and vaccine recommendation for postexposure prophylaxis of certain diseases
eg Hep B, rabies, tetanus
May be affected by circulating antibody to the antigen
Live parenteral vaccines - they may replicate
Interval between antibody and measles and varicella containing vaccines
If live vaccine given first
Wait 2 weeks before giving antibody
In measles and VZV vaccines, if antibody is given first
Wait 3 months or longer before giving the vaccine
Washed RBC interval
0 months
Hepatitis A IG interval
3 months
Measles prophylaxis IG
(Immunocompetent recipient) interval
6 months
Plasma/platelet product interval
7 months
Intravenous immune globulin IVIG interval
7-11 months
