Vaccines Flashcards
Variolation
Inoculating with dried pustules.
Dr. Emmanuel Timoni
Documents variolation
Lady Mary Worthey Montagu
Variolates children in front of court
Cotton Mather
Survives major smallpox outbreak due to variolation
Edward Jenner
Inoculates James Phipps with cowpox and observes immunity to smallpox.
Louis Pasteur
Develops attenuated vaccines against anthrax and rabies.
Jonas Salk
Develops inactivated polio vaccine 1952
Reasons that smallpox eradication was feasible
Restricted to humans, acute infection, readily detectable symptons, does not undergo high rates of mutations.
Goals of vaccination
Establish the adaptive immune response before infection, induce herd immunity
Vaccination for extracellular pathogens should
Aim for humoral immunity
Vaccination for intracellular pathogens should
Aim for cell-mediated immunity
5 types of vaccines
Live-attenuated, killed, subunit, toxid, conjugate
Live-attenuated
Weakened live pathogens.
Ways to weaken live pathogens
Culture adaptation, egg adaptation, temperature-adaption.
FluMist
Temperature sensitive mutant that only grows in cooler nasal passages.
Advantages of LAV
mimic natural infections’ mucosal immune responses. Generates robust and durable immunity
Disadvantages of LAV
May cause disease, potential for reversion mutation. Can be contaminated?
Killed vaccines.
Inactivated pathogens.
HepA vaccine
KV against hepatitis A, viral liver disease. Inactivated by formalin. Developed by Maurice Hilleman
Advantages to KV
Safe, easy to make
Disadvantages to KV
Shorter length of protection, only elicits antibodies, requires booster shots.
IPV vs OPV
Safe, not so effective vs. very effective not so save polio vaccines. Higher frequencies of cases makes OPV more attractive.
Antigen and adjuvant
Pathogen-derived molecule and substances that enhances immune response.
Subunit vaccines
Involve the most immunogenic antigens from a pathogen.
SV production
Grow in cells and fragment or express antigens recombinally.
Hepatitis B vaccine
Subunit vaccine.. Developed by Maurice Hilleman. Now expressed in yeast.
Advantages to subunit vaccine
Safe
Disadvantages.
May require boosters, knowledge is required, more expensive.
Toxoid vaccines
Modified pathogenic toxins are inactivated.
Tetanus vaccine
Tetanus toxin is inactivated by formaldehyde. Adsorbed to adjuvant (alum)
Toxoid advantages
Safe
Toxoid disadvantages
May require boosters, requires purification, requires adjuvants.
Adjuvants
Can act as a carrier, prolonging and facilitating antigen presentation (alum, oil emulsion) or be immunostimulatory (bacterial wall components)
ALUM
Until recently the only licensed adjuvants approved for human use
TLR agonist
Elicits immune response.
Conjugate vaccines
A non-immunogenic bacterial component eg. polysaccharide can be conjugated to a immunogenic carrier protein
Pneumococcal disease vaccine
Pneumococcal polysaccharide is conjugated to nontoxic diphtheria carrier protein.
Advantages to CV
Safe, effective
Disadvantages to CV
Costly.
DNA based vaccines
Immunogenic gene are inserted into host. Future.
Microbial vector vaccines
A virus carries immunogenic gene.
Virus like particles
Mimicks the structure of virions.
