Adjuvants, Vaccines, immunity and antiviral agents Flashcards
What does it mean that a vaccine is live (weakened) or killed?
A live vaccine often only needs to be taken once (more effective), but a killed vaccine (less effective) needs to be injected several times (booster-doses).
Live vaccines are a mutation and doesn’t grow well in humans, which will provoke an immune response.
A killed vaccine is dead and will provoke a smaller immune response when injected. All proteins are present.
What is meant by adjuvant in the context of vaccination? Give two examples of vaccine adjuvants.
An adjuvant is an immune enhancement and will provoke a immune response. A substance that potentiates and/or modulates the immune responses to an antigen.
Examples:
- microbial products (ex LPS) to trick immune system to respond in a wanted way.
- cytokines and chemokines, e g IL-2, IL-12, TNF. Ex aluminum.
What different types of vaccines are there?
- Live attenuated vaccines – the virus does not grow well in human cells anymore. Low risk of virus going back to its pathogenic form.
- Inactivated killed vaccines – all proteins present
- Recombinant vaccines – example only surface parts of virus
- Subunit vaccine – only part of virus
- Peptide vaccine – synthetic viral aa
- RNA & DNA vaccine – safety as killed vaccine but efficiency as live vaccine.
- Conjugate vaccine – conjugate of bacterial polysaccharide and extremely immunogenic substance. It is degraded & displayed on MHC class II. The T cells have been sensitized to the immunogenic substance before, which causes the T-cell to activate B-cell to produce anti-polysaccharide antibodies.
Explain briefly what is meant by herd immunity (in the context of vaccination).
Herd immunity offers more protection to an unvaccinated individual than if there is no herd immunity. The probability of the disease spreading decreases because of the high number of vaccinated (immune) people and therefore a reduction in the natural reservoir for infection.
What is the difference between active and passive immunization?
Active immunization involes injecting a patient with dead or cultured pathogens to create an inflammatory responses. The IR will lead to the formation of long lived memory B-cells with affinity towards that specific pathogen. (Adjuvants are usually used)
Passive immunization indicates a temporary immunity and no immunological memory. Anti-viral drugs contains passive antibodies and once given to a patient, it will provide passive immunization.
