BIOL 2420 (Microbiology) - Chapter 17: Vaccines and Serology

first vaccine inoculated against

smallpox

difficulties vaccinating against eukaryotic pathogens

hard to counter pathogens that look like our cells

danger of polio in the 1960s

killed many people, and paralyzed more

contemporary location of polio

more common in less developed countries

danger of measles 

highly contagious

vaccine against measles

MMR

sunsetting

pathogens that have been eradicated from the world

important reason vaccines prevent pathogens

prevents diseases, reduce mortality, and prevents epidemics/pandemics

passive immunization

sources include natural maternal anitbodies/antitoxins and immune globulins, protective antibodies transferred from another person or animal; temporary effects

active immunization

natural infection and vaccines, toxoids; relatively permanent

types of active vaccines

attenuated, inactivated (killed), subunit vaccines, conjugated vaccines, toxoids, genetically engineered

attenuated viruses

live, weakened viruses or bacteria that are weakened in a lab

importance of vaccination in immune response

“primes” the immune system so you have a secondary response to the pathogens

Inactivated vaccines

Inactivated by heat of chemical agents such as formalin, phenol, or acetone

subunit vaccines

contain purified parts of pathogens (e.g., antigenic polysaccharides from a bacterial capsule)

conjugated vaccines

the use of purified antigenic polysaccharides combined with antigenic proteins to make them more immunogenic (these vaccines are also called protein conjugate vaccines) 

toxoid vaccines

vaccines that stimulate the production of antitoxins (they require boosters)

genetically engineered vaccine

the use of bacteria to produce the protein antigens found in viral capsid and the bacterial cell envelopes

advantages/disadvantages of attenuated vaccines

A: long life immunity, humoral cell mediated; D: danger to immunocompromised population, could revert to virulent

advantages/disadvantages of inactivated vaccines

A: no disease D: humoral only, requires boosters

advantages of subunit vaccines

A: cannot cause disease

advantages/disadvantages of genetically engineered vaccines

A: does not really cause disease, could have more potent immune response, D: not properly developed at this time

herd immunity

where most of the population is immunized by vaccination

serological tests

tests that determine the presence of specific antigens or antibodies in the blood serum

two criteria of a “useful” serological test

specificity, sensitivity

specificity

probability that a positive test will not be reactive if a specimen is a true negative

sensitivity

probability that the test is reactive if the specimen is a true positive

MOA of agglutination

occurs due to the cross-linking of antibodies with particulate antigens

hemagglutination test detects

what type of blood

which antibodies would bind to type A+ blood and cause hemagglutination

anti-B antibodies

indirect agglutination

involves the use of secondary particles to bind cause agglutination

MOA of ELISA

antibodies affect the antibodies present within the serum

MOA Of immunochromatographic assay

zone antibodies work to trap them on the test strip

advantages of fluorescent antibody technique

can directly visualize where an antibody is present

direct fluorescent antibody technique

uses a primary antigen that binds to the target antigen

indirect fluorescent antibody technique

uses both a primary antigen and a secondary antigen that binds to the target antigen