Vaccination
Types of acquired immunity
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• natural active - antigens enter body naturally, body - RNA vaccines - mRNA strand that codes for
produced antibodies antigen of interest
• natural passive - antibodies pass from mother to • mRNA taken up by APCs, translate mRNA to
baby protein antigen, present to T cells
> vaccine components
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• artificial active - antigens introduced in vaccines
• antigen
• artificial passive - antivenom, immune serum
• adjuvants - additive used to enhance efficacy
- live attenuated vaccines - living but weakened microbes
of weak antigens, induce strong immune
• bacteria, viruses response
• closely mimics actual infection, longer immunity w/out - help recruit immune cells
boosters - dose sparing, more rapid immune response,
• microbe replicates in body - remains in body longer, enhance antibody/cellular immune response
increase immune response • preservative - prevent contamination
• risks - back mutation to virulent form • stabilizer - keep vaccine effective
- immunocompromised should not receive, pregnant >
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licensing
women • preclinical - lab studies/animals
• MMR, chickenpox, shingles, rotavirus, some infleunza • phase 1 - small doses in 10s of healthy
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inactivated whole agent vaccines - whole killed microbes volunteers, safety, side effects, assess immune
• less effective than attenuated - often need boosters response
• rabies, some influenza, IPV (polio), hepatitis A, HPV • phase 2 - hundreds of target people, some
subunit vaccines - antigens of microbe, stimulate best Ab
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effects, how much is needed
response • phase 3 - thousands of targets, effectiveness
• recombinant subunit vaccine - Ag made by genetically • phase 4 - hundred thousands, potential adverse
engineered organisms (hep B produced by yeast) effects
• not as effective - some require boosters
• safer - no replication in host, fewer side effects
• meningococcus, hep B, some influenza, acellular
pertussis (ap in DTAP)
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- toxoid vaccines - against toxins produced by pathogens
• inactive toxins - no toxic effects, inactivated by
chemical treatment/heat
• series of injections and boosters for full immunity
• diphtheria, tetanus (DTAP, Tdap)
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- conjugated vaccines - combination of antigen and protein
• haemophilus infleuenzae type B (HiB), pneumococcus,
meningococcus
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recombinant vector vaccines - select genes from pathogen
inside harmless virus/vector
• erbevo (ebola), J&J COVID
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nucleic acid vaccines - DNA/RNA induce our cells to make
pathogen specific proteins, cause immune response
• killer T cells destroy infected cells, B cells/helper T
induce antibody production
• covid mRNA (Pfizer, Moderna)
- often require boosters, ultra cold storage