-refers to the deliberate induction of protective immunity to a pathogen by the administration of killed or non-pathogenic forms of the pathogen, or its antigens, to induce an immune response

-Prevent occurence of disease

-Vaccinations are much cheaper then treatment

-Vaccines can sometimes prevent a disease for which no effective medical treatment is available

-Not enough vaccine is available to protect humanity from dreadful diseases

Scientific Limitation - constantly changing infectious agents, good @ changing surface antigens. (HIV, Influenza, Malaria)

Non-scientific reasons - financial, legal, and political reasons. Across planet, dont have enough vaccines to cure everything

Observation of life long immunity to plague and small pox by Egyptians, Indians, Chinese, and Greeks.

-If exposed and lived then resistance would be possible

First disease against which vaccine was used

(Smallpox)

-High mortality rate, survivors scarred for life

-Never came down with it a 2nd time

-FIRST vaccine developed on observation vs. origin

-Ancient history used materials from smallpox pustules to put in healthy arm as preventive measure against smallpox (variolation)

Inoculating healthy arm with smallpox pustules to prevent against development of smallpox.

Variola means smallpox in Latin

-Only 1 in 100 developed full-blown smallpox infection

-Early 1700's Lady Mary Montagus practiced variolation in London (convinced people)

Late 1700's - realization that coxpox provided protection against smallpox.

May 14th, 1796 - pustular fluid from cowpox vescicles used 

Vaccus means cow

Vaccinia - cowpox virus

Vaccination - inoculation of vaccinia

Cowpox and smallpox viruses share some surface antigens

-immunization with cowpox induces antibodies against cowpox surface antigens

-cowpox antibodies bind to/neutralize smallpox virus

-Memory laid down for cowpox; cross-reacts with smallpox; allows us to protect against smallpox

Louis Pasteur

1st immunological experiment

B.anthracis was heated and chemically inactivated and ultimately kept the host alive vs. if it was live which lead to death.

In 1885- He administered rabies vaccine to Joseph Meister and he lived

-Vaccinations reduced morbidity rate of diseases

Active Immunization

(A for antigen)

Passive Immunization

administration of preformed antibodies to treat infection (in diptheria, tetanus, snake bite)

-Short duration

Ex. child has diptheria, but hasnt been vaccinated. Given antibodies that neutralize toxin at its initial stages.

-vaccines cause serious side affects that lead to neurological damage (really?)

-only because they occured at same time.

-opposers against vaccination believe in herd immunity

protection of an unvaccinated person when around healthy people because chance of interacting w/people with problem not possible.

-On flip side, if unvaccinated person went to somewhere where there was unhealthy people its more likely.

Most of vaccines against bacterial infections are from killed bacteria

-Some use live-attenuated bacteria while others use inactivated toxins, cell extracts, or polysaccharides

BCG (Bacille Calmette-Guerin, weakened Mycobacterium bovis) against M. tuberculosis

-reducing virulence but still viable

DTP -"P" vaccine Bordetella pertussis (whop cough)

Salmonella paratyphi (paratoid fever)

Vibrio cholerae (Cholera)

Yersinia pestis (plague)

-most successful bacterial vaccines.

-inactivated by treatment with formalin, toxin loses pathogenicity but protein still capable of generating an immune response

Ex.Tetanus and Diphtheria toxoid (DTP)

DTP originally used, DTap now used more

D&T-detoxified forms of bacterial toxins

Soluble proteins- phagocytes not involved

-Antibodies neutralize toxins circulating in the bloodstream, toxins cause these diseases

-Dont illicit strong response to soluble protein, need multiple needle stick

D&T no side effects, P does

-Infants got side effects

-P = whole killed B. pertussis, some parts toxic

aP=toxoid form of pertussis plus surface antigen

-Simple vaccines prob wont cause side effects, more likely to target desirable immune response, but may not trigger memory

Subunit vaccines

-developed from purified antigens from microbes or produced by recombinant DNA technology (D,T (toxoidsm and aP)

-may be composed of polysach antigens w/capsules

-effective for adults, kids<2 years and elderly doesnt work, dont develop good T-independent response

-used for B cells w/no memory capabilities

-polysacch antigen coupled with protein (toxoid) to induce T-cell response.

-allow opsonization->phagocytosis, complement activation, and neutralization of antigen.

-tricked @ making B-cell memory cell that recognizes polysaccharide antigen.

-conjugate vaccine against H. influenza B

-target is capsular polysaccharide

-its recognized by specific Bcell receptor, antibody made and specific for polysaccharide component

-peptide recognized by Th2 cell, plasma cells made

Goals:identify best antigens/epitopes of antigens, make them in lab, use them as vaccines

-We need to screen genetic material for great epitopes with good access to get to protein

-Trial and error procedures

DNA absorbed onto gold particles, put in muscle.

-Deliver it as vaccine, displayed on muscle cell surface.

-Lasts long enough to give robust immune response

-Called Naked DNA Vaccines

Positives/Negatives

"DNA Vaccines"

Merit:can be stored dry, less expensive to make, effective even w/o using adjuvant

Demerit: may induce autoimmune response (lupus)

Adjuvant

USA=Alum(aluminum hydroxide)

substance that nonspecifically enhances immune response to antigen

-mediated by concentrating antigen in site where lymphocytes are exposed to it (depot effect)

-slow release of antigen, prolonged exposure

-induction of cytokines (regulate lymphocyte function)

-Induce right sort of immunity (illicited if on outside of cell or inside)

-Be stable on storage (not have to keep cold)

-Have sufficient immunogenicity (doesnt protect from exposure, to illicit robust response we have to continue to give them booster)

-contamination, killed vaccines may not have been properly killed, microbes adept @ picking up genetic material from environment.

-Can revert attenuated virus to wild type

Patients: some can be more sensitive than others

-immunocompromised, dont take live bacteria!!

-Patches that prevent shots

-Edible vaccines-genetically engineered plant

-Reduce number of doctor visits for shots; combination versus simultaneous vaccines