Principles of vaccination

what is variolation?

an early method of vaccination where people collected pox material from patients who had recovered and give to others to protect them from the disease

who discovered small pox vaccine? and how?

Edward Jenner discovered that a disease of cows that causes mid diseases in human could protect agasint smallpox through vaccination with cowpox.

what is a vaccine?

induces active immunity in individuals and protects from disease

What is active immunity?

elicits an adaptive immune response

it will be slow - a week to two weeks but produces memory

can be artificially induced with the vaccine or naturally induced infection

body is exposed to an antigen

immunity is long lasting

what is passive immunity?

not exposed to antigen but instead antibodies are transferred either IGA from breast milk, or IgG through placenta, or injection of antibodies

immediate but short lived

what is a live vaccine?

weakened form of a virus or bacteria because they contain mutations that make them less virulent

replicates in the body but don’t cause disease because they have reduced virulence

the body has extended exposure to the antigens and can produce the strongest most protective response

disadvantages: people with weakened immune systems cannot receive attenuated vaccine

mutations can occur which can lead to an attenuated strain to become more virulent

genetically engineered can be used to add a piece of a dangerous virus like ebola to a virus that does not cause disease like chimeric vaccine

Examples of live vaccine: MMR or oral polio vaccines

What are inactivated (killed) vaccines?

viral particles or bacterial cells that have been treated with chemicals

using this vaccine presents with many antigens

cannot revert

disadvantages

multiple booster required

What are subunit vaccines?

inactivated form of toxin

generally safe and few side affects

disadvantages

multiple boosters

What is DNA vaccine?

the gene for a viral or bacterial protein would be injected and would be transcribed and translated by the host producing a protein

stable and requires no refrigeration

What is RNA vaccine?

messenger RNA for a viral or bacterial gene would be injected, microbial proteins would be produced by host

advantages

easier to produce

easier to produce different type of vaccines

What are adjuvants

subunits vaccines contain them

adjuvants are substance like aluminum hydroxide that stimulate your body to produce a stronger response to the vaccine

the more effective the less safe, the less effective the more safe it is

how are vaccines developed?

laboratory research - identify forms of pathogen that are week

clinical trials