What is a Vaccine?
A vaccine is a suspension of microbes, which have been attenuated, killed, and or fractioned, and produces an immune response upon injection into a host.
What is attenuated?
Types of Vaccines
Attenuated, whole-agent Vaccine
*Living Agent, usually virus
*Agent usually reproduces in host, therefore, generally provides most effective and long-lived immunity.
*Microbe is either avirulent or less virulent than the disease-causing agent
*Risk of Back mutation
What is vaccine back-mutation?
Risk of back-mutation to virulent forms may cause disease, particularly in an immunocompromised recipient
Examples of Attenuated, whole-agent vaccines.
Measles, mumps, rubella (MMR)
Oral polio (Sabin)' small pox, TB, nasal influenza vaccine.
Inactivated whole-agent Vaccine
Microbe is killed, usually by chemical treatment with phenol or formalin.
Examples of Inactivated whole-agent Vaccine
Rabies and injected influenza vaccine
Injected polio (Salk)
Why get vaccinated each year for seasonal flu?
In order to be protected against the strains that have mutated.
Examples of Toxoid Vaccines
Tetanus and diptheria
Microbes and fragmented (acellular)
This vaccine has the lowest risk for side effects
Examples of subunit vaccines
Produced by genetically-modified yeast.
Microbial polysaccharides are coupled with proteins to enhance T-cell response
Example of Conjugated Vaccine
Haemophilus influenza b