In a Clinical Trial of a New Antiviral Vaccine Composed

question 7

Multiple Choice

In a clinical trial of a new antiviral vaccine composed of a recombinant viral peptide and adjuvant,4% of the healthy recipients did not show evidence of response to the immunization.Further investigation revealed that all the nonresponders expressed the same,single allelic variant of HLA-DR but all the responders were heterozygous for HLA-DR alleles.Which of the following is the most likely explanation for this finding?

• A)Response to the vaccine requires T cell recognition of complexes of the viral peptide with HLA-DR,but the peptide cannot bind to the allelic variant of HLA-DR found in the nonresponders.
• B)The nonresponders could not express class II MHC proteins.
• C)The viral peptide is not an immunodominant epitope.
• D)The nonresponders underwent determinant selection of another viral epitope.
• E)Because of technical errors,the nonresponders had not received adequate doses of the vaccinE.

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Definitions:

Price Discrimination

A pricing approach in which the same provider sells identical or nearly identical products or services for varying prices across different markets.

Monopolists

Individuals or firms that are the sole providers of a unique product or service in a market, with the power to control prices and exclude competitors.

Price Discrimination

A pricing strategy that charges customers different prices for the same product or service based on what the seller thinks they can get the customer to agree to.

Elastic Demand

A situation where the quantity demanded of a good or service changes significantly as its price changes.