Idealness
What does the history of vaccine include (hint: cowpox and pasteur)
China - 15th century = variolation against smallpox
Edward Jenner - 1798 = Vaccinia virus (cowpox) protection against smallpox
Louis Pasteur - 1880s = Fowl cholera (coins the terms "vaccine - vaccination"), anthrax, Rabies
What makes a vaccine easily administered?
preferably without a needle
What are the types of immunization
Passive - goes into artificial or natural
active - goes into artificial or natural
Active artificial - goes into living organisms, dead organisms (killed vaccines), metabolic products (toxins), DNA or RNA, synthetic antigens (subunit vaccines
Active artificial living organisms - goes into fully virulent, heterologous, attenuated, live recombinants
What are DNA/RNA vaccines? delivery?
RNA or DNA encoding an antigen
Delivery - to cell cytosol (RNA) or nucleus (DNA), gene gun or liposome nanoparticle delivery
What is antigenic shift in relation to influenza virus
Recombining genome of human, poultry and/or swine viruses in one cells
What does the ideal vaccine include?
Safe for all individuals
Induces PROTECTIVE response
Long lasting
Overcomes maternal immunity
easily administered
single dose
inexpensive to produce
Stable
What makes a vaccine stable?
avoids requirement for cold storage
avoids necessity for reconstitution
What are live recombinant vaccines
Vectors: vaccinia, attenuated adenovirus, attenuated salmonella
Insertion of sequence encoding antigens of pathogen into vector virus/bacterium - vaccinia/adenovirus expressing rabies proteins, COVID-19
What are advantages of live recombinant vaccines
Effective humoral and cell-mediated immune responses
single inoculation
What are the disadvantages of live attenuated vaccines
Risk of reversion to virulence
shedding of organism into environment
care needed in storage and handling - cold chain required
What makes a vaccine safe for all individuals?
Non-living vaccines inherently safer
Non-toxic
Lack side effects
What is hemagglutinin and neuramidase
Influenza virus types (i think)
Hemagglutinin - cell attachment = 13 major types
Neuramidase - release of newly formed virus = 9 major types
What are killed vaccines
Whole virus or bacteria killed by heat or chemical treatment - termed bacterin in case of bacteria
Rabies and polio vaccines
What are advantages of subunit vaccines
Safe
longer shelf life
What are disadvantages of subunit vaccines
Must identify subunit eliciting protective immunity
multiple administrations
poor cell mediated immunity
requires an adjuvant
What makes a vaccine induce a protective response?
Cellular versus humoral immune responses
broad cross protection against variants
right antigen / right conformation
What are the three types of influenza virus
Influenza A B C
many subtypes
What are subunit vaccines
Contains 1 or at most a few components of the infectious agent
Usually recombinantly produced
What are killed vaccines advantages
Relatively safe
longer shelf life
What are disadvantages of live recombinant vaccines
Potential reversion to virulence
pre-existing immunity to the vaccine carrier or vector
limited use per individual due to anti vector response
What classifies a vaccine as long lasting?
lifetime protection
What is antigenic drift in relation to influenza virus
gradual accumulation of mutations which avoid binding of antibodies
What are live attenuated vaccines
A live infectious agent from which virulence has been removed (reduced) - by culture or mutagenization or molecular methods = sabin polio vaccine (grows virus in eggs at sub-physiological temps
What are the advantages of live attenuated vaccines
rapid onset of immunity
single dose often adequate
adjuvants unnecessary
induction of cell-mediated immunity
Persistence stimulates long-lasting immunity
Replication can amplify responses at systemic and mucosal levels
What are killed vaccines disadvantages
Loss of antigenic properties due to chemical treatment
poor mediate immunity (not being expressed inside your cells)
usually require an adjuvant