Vaccines Flashcards
What are the goals of vaccination?
To prevent symptoms and spread of illness (impossible to stop all infection).
What are some criteria a virus must exhibit to merit vaccine development?
What are some important considerations for the vaccine?
Causes significant illness, has relatively few and unchanging serotypes, and is associated with lifelong immunity.
The vaccine should be safe, elicit good immunity, and be practical (cheap, stable, and useful).
Why are some vaccines given in multiple regimens over months or years?
What is the molecular goal of vaccination?
What about viral structure makes them less apt to avoid antibodies?
After proliferation, lymphocytes must “rest”.
Formation of antibodies against a viral antigen–neutralization, ADCC, opsonization. Sometimes even lysis!
Capsid structure is usually repetitive; this is favorable for antibody interaction.
What are the advantages and disadvantages of inactivated vaccines?
What are the advantages and disadvantages of live-attenuated vaccines?
Which category does Salk’s vaccine fall under?
Inactivated vaccines are (generally) safe and stable. They do not elicit mucosal immunity, and are not long-lasting.
Live-attenuated vaccines elicit longer, broader immunity. They may reactivate and require careful storage.
Salk’s is inactivated (Sabin’s is live).
How does virus “attenuation” occur?
Why is this attenuated virus less apt to harm the human host?
In the case of polio, the virus is cultured in tissue of another organism, and then recollected.
The virus is not well-equipped to invade or manipulate human cells (different polymerases, ribosomes, etc)
Do live-attenuated or inactivated vaccines exhibit each of the following traits:
Requires cold storage
May elicit imbalanced immune response
Mimics natural infection
Can spread to close contacts of the recipient
Requires multiple boosters
Live-attenuated
Inactivated
Live-attenuated
Live-attenuated
Inactivated
What is a recombinant virus?
How are these viruses grown?
What benefit can recombination provide for univalent vaccines?
A manufactured vector which carries genes from one or more viruses.
We may directly transfect cells with the desired RNA, or we may select using helper viruses (not clear on this–also ongoing research)
Knocking out pathogenicity factors (virulence genes) can quickly generate attenuated vaccines.
What are subunit vaccines? Name two examples.
Vaccines which only contain one or a few antigens–they are not complete. HBsAg is an example which spontaneously constructs itself. HPV vaccines are also subunit recombinant vaccines.
Describe the concept and goal behind new peptide-based vaccines.
Ideally, we could produce peptide vaccines containing the most immunogenic epitopes (fine-tune MHC presentation). These would be safe and relatively stable.
Describe the concept and goal behind DNA inoculation.
Host cells would be persuaded to take up DNA (eg with a gene gun), and would express the immunogenic proteins. Full and long-lasting immunity would develop without infection risk.
Add cytokine/costim genes, CpG inserts…
