Immune memory and vaccines Flashcards
Memory B cells
Don’t contribute to acute infection immune response
Once antigen is encountered again - memory B cells proliferate and differentiate into plasma cells and start producing antibodies
On subsequent responses to infection – IgG response is much faster and larger
IgG is more readily produced by memory B cells and measuring IgG is the most useful marker of immunity
Memory T cells
after first time antigen is encountered, CD4 and CD8 cells with specific TcRs rapidly proliferate and differentiate
Most disappear after acute infection
- However large amount of specific CD4 and CD8 cells stick around as memory T cells and await subsequent infections
- Where they can proliferate and differentiate faster and provide a more rapid specific immune response
- Very difficult to measure T cell immunity (CD4/CD8) and is not done in practice
Subunit vaccines:
Only contain specific parts of the organism (such as the exact antigen required) to stimulate an immune response and the subsequent immunity to the disease.
They cannot cause an infection and are safe for patients with immunosuppression (although they may not have an adequate response).
Inactivated vaccines
Inactivated vaccines contain pathogens that have been treated to kill them (e.g. with heat) to make them unable to cause an infection but still contain all the necessary antigens to stimulate an immune response.
These are also safe for patients with immunosuppression (although they may not have an adequate response).
Live attenuated vaccines
Live attenuated vaccines contain a weakened version of the virus, and are still capable of causing the infection and should be avoided in immunosuppressed patients.
The following vaccines are live:
== Measles, mumps and rubella vaccine (all three contain weakened viruses)
== BCG (contains a weakened version of tuberculosis)
== Shingles (contained a weakened varicella-zoster virus)
Nasal influenza vaccine (not the injection)
