Microbiology 16: Bacterial And Viral Vaccines Flashcards
What does the R0 of a disease tell you ?
The number of people that 1 infected person will infect on average
Outline the immune response to a new pathogen
1- APC present antigens from the pathogen to Naive T helper cells.
2- Naive T helper cells become activated and activate naive B cells
3- Some B cells become activated to plasma cells which can produce antibodies against the pathogen
4- The activated T cells can also activate T killer cells which destroy the pathogen
5- Memory B and T cells are formed to create adaptive immunity
What is an attenuated vaccine ?
Give 4 examples ?
Live organism modified to be less virulent
MMR, yellow fever, VZV, Typhoid
What is an inactivated vaccine ?
Give 3 examples?
The microorganism is destroyed and its particles injected
Influenza, Pertussis, Hep A,
also (polio (SALK), cholera)
What is a toxoid vaccine ?
Give 2 examples ?
A vaccine containing inactivated toxin of a pathogen
Diphtheria, tetanus
What is a subunit vaccine ?
Give 2 examples ?
A protein component of the pathogen is injected
Hepatitis B virus, HPV
What is a conjugate vaccine ?
Give 3 examples ?
Poorly immunogenic antigens are paired with an adjuvant which stimulates the immune system to respond
(encapsulated bacteria NHS)
Meningococcus (Men c, Men b etc)
Pneumococcus (PCV)
Haemophilus Influenza B (Hib)
What is a heterotrophic vaccine ?
Give one example ?
Using a pathogen that infects other animals but does not cause disease in humans
BCG
Give 2 contraindications to most live vaccines ?
Pregnancy
Immunocompromised patients
Is MMR safe in HIV ?
Yes (one of the exceptions in live vaccines)
what is herd immunity
form of immunity when vaccination of a significant proportion of the population provides a measure of protection for individuals who are not immune
herd immunity threshold = 1 - 1/R0
what are the 3 main types of memory cells
memory B cells
memory T killer
memory T helper
what is the difference between monovalent and multivalent vaccines
mono - targets one strain
multi - targets several strains
name some components of a vaccine
stabilisers aluminium hydroxide - common adjuvant preservatives antibiotics - prevents contamination trace components
list come prerequisites for successful disease eradication
no animal reservoir
antigenically stable pathogen with one/few strains
no latent reservoir
vaccine induces a lasting and immune response
