MI 1.4

case-control study

study where a group of individuals with the diseases, referred to as cases, are compared to individuals without the disease, referred to as controls

cohort study

study where a group of exposed individuals (individuals who have been exposed to the potential risk factor) and a group of non-exposed individuals are compared

epidemic

affecting an atypically large number of individuals within a population, community, or region at the same time

epidemiology

a branch of medical science that deals with the incidence, distribution, and control of disease in a population

herd immunity

resistance of a group to an attack by a disease to which a large proportion of the members of the group are immune

inoculation

introduction of a pathogen or antigen into a living organism to stimulate the production of antibodies

plasmid

small ring of DNA that carries accessory genes separate from those of the bacterial chromosome

recombinant DNA

DNA molecule made in vitro with segments from different sources

vaccination

procedure that presents the immune system with a harmless variant of a pathogen, thereby stimulating the immune system to mount a long-term defense against the pathogen

vaccine

harmless variant of a pathogen that stimulates a host's immune system to mount defenses against the pathogen

what is edward jenner known for?

developed the first vaccination by inoculating cowpox virus to protect patients from smallpox

APCs

- antigen presenting cells
- breaks the vaccine antigen apart and "wears" it to alert T helper cells

T helper cells

T cells that are stimulated by antigen to provide signals that promote immune responses

naive B cells

- B cells that have not been exposed to an antigen
- can turn into plasma B cells or memory B cells

plasma B cells

produces antibodies

T cells

sends cytokines to immune system so body can produce what it needs

cytokines

chemical messengers produced by t cells

cell-mediated response

the response of T cells to antigens

memory B cell/memory T helper cell/memory killer T cell

cells that "remember" immune responses

subcutaneous

under the skin

intramuscular

within the muscle

intradermal

within the skin

which route of administration has the longest absorption time?

intradermal

R_0 (R sub 0)

# of people 1 person can infect with the disease

threshold

% of population that must be vaccinated to achieve herd immunity

inactivated vaccines

- killed w/ heat, chemicals, or radiation
- harmless but still recognizable
- requires larger doses + more boosters

live attenuated vaccines

- longer lasting + requires fewer boosters
- elicits strong immune response
- may mutate
- not for the immunocompromised

toxoid vaccines

purified/inactivated toxin produced by bacteria

conjugate/subunit vaccines

- part of pathogen (protein, gene, piece of capsule)
- may require "carrier" virus/cell to make protein copies

mRNA vaccines

mRNA wrapped in lipid sphere that codes for protein of virus

what does a purifier do?

separates the pathogen from other materials

live vaccine example

smallpox

attenuated vaccine example

measles

killed vaccine example

polio

toxoid vaccine example

tetanus

subunit vaccine example

hepatitis B

naked DNA vaccine example

HIV

restriction endonucleases

- "molecular scissors"
- enzyme that cuts DNA when it recognizes a specific base sequence

ligase

- "molecular glue"
- enzyme that connects ends of DNA molecules together

sticky ends

single stranded ends of DNA left after cutting with enzymes

what is john snow known for?

- father of epidemiology
- investigated source of cholera outbreak to prove contaminated water was the source

gene

section of DNA that codes for a particular characteristic

alleles

different forms of a gene that codes for a particular trait

genotype

combination of parent's alleles

phenotype

physical characteristics

probability formula

# of desired outcomes/# of total possible outcomes

food-specific attack rate formula

# of people who ate a certain food and became ill / total # of people who ate that food

active immunity

- antigen activates the immune system to produce immune substances
- includes natural immunity and vaccine-induced/artificial immunity

natural immunity

acquired from infection with the actual disease through exposure to the disease organisms

vaccine-induced/artificial immunity

acquired through the introduction of a killed or weakened form of the disease organisms through vaccination

passive immunity

individual receives antibodies that were produced actively in the body of another person