Define immunogen - ✔️✔️a substance that induces a specific immune response- can
be a protein, polypeptide or polysaccharide
Define adjuvant - ✔️✔️a substance that enhances the body's immune response to
weakly immunogenic antigen by promoting inflammation
How does adjuvant promote inflammation - ✔️✔️Promotes slow release of antigen →
prolonged immune stimulation → inflammation
Binds to PRRs → inflammatory response
Define Toxoid - ✔️✔️a chemically modified toxin from a pathogenic microorganism,
which is no longer toxic but is still antigenic and can be used as a vaccine to form
protective antibodies
Adaptive artificial immunity - ✔️✔️Passive: Antibody transfer through injection
Active: Vaccination
active immunization - ✔️✔️Stimulate own immune system to elicit immunity
Long-term protection is desirable-- memory
passive immunization - ✔️✔️Individual acquires immunity through the transfer of
antibodies formed by immune individual or animal
Temporary protection of 1-6 weeks due to antibodies being metabolized- antibody half
life
Neonatal antibodies as example-IgG/IgA
Neonates are protected for the first six months of life by maternally derived antibody.
What for of immunization is this? - ✔️✔️natural Passive immunization
What immunological phenomenon is the basis ofvaccination? - ✔️✔️Immunological
memory
Q&AIn general, when is maternally-derived IgG no longerdetectable in the neonatal
circulation? - ✔️✔️6-8 months of age
Most effective ways to prevent infectious diseases: - ✔️✔️Prevent
transmission:Sanitation and Vector Control (for pathogens that spread through insect
bites)
Prevent infection or disease: Vaccination/immunization when possible--Achieve 'herd
immunity or Disrupt the chain of infection
, herd immunity - ✔️✔️the resistance to the spread of a contagious disease within a
population that results if a sufficiently high proportion of individuals are immune to the
disease, especially through vaccination.
Immunity can be achieved by - ✔️✔️Active or passive immunization
Natural Adaptive Immunity - ✔️✔️Active: Immunity that is gained from infection with a
live pathogen.
Passive: Maternal- through IgG crossing the placenta or IgA through breast milk
Two main categories of vaccines - ✔️✔️Live attenuated vaccines• -- Whole pathogen
Inactivated vaccines (require adjuvant/boosters)• Whole pathogen• Subunit Capsular,
toxoids RNA vaccines (most recent development)
What is required for a good adaptive immune response - ✔️✔️Inflammation
advantages of attenuated vaccines - ✔️✔️mimic natural infection, mucosal immunity,
stimulates PRRs, induces abs, CD4,CD8 responses
Advantages of subunit vaccines - ✔️✔️Reduced risk of adverse events(no risk of
infection or spread
Disadvantages of subunit vaccines - ✔️✔️Must know the antigens to which immunity
isgenerated
Do not induce CD8 T cell response
Adjuvant and booster injections required
Subunit Vaccines examples - ✔️✔️Toxoid vaccine (non-toxic version of toxin)--
Diptheria-Tetanus-acellular Pertussis (DTaP)
Conjugated polysaccharide vaccine HiB
Recombinant subunit vaccine Hepatitis B
Viral vector vaccine--Oxford/AstraZeneca SARS-CoV-2 vaccine
RNA vaccine--Pfizer and Moderna SARS-CoV-2 vaccines
Protein Subunit vaccines examples - ✔️✔️DTaP
Disadvantage of polysaccharide subunit vaccine - ✔️✔️It is purely immunogenic in
target populations-- which are kids below the age of 2 y/o
They induce T-Cell independent immune response with no immnologicalmemory
produced
Only Produce IgM