Why Is There No Lifelong Vaccine Protection Against Flu as There

question 3

Multiple Choice

Why is there no lifelong vaccine protection against flu as there is by a measles vaccine?

• A)The variety of flu strains is too great to be captured by a single vaccine.
• B)Flu can escape host immunity by evolving new variants that re-infect hosts.
• C)The flu is too virulent to effectively vaccinate against.
• D)The antigenic memory against flu has a short half-life.

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Definitions:

Money Supply

The overall sum of money available in an economy at a designated moment.

Government Expenditures

Spending by government agencies on goods, services, and projects to fulfill public policies, which can influence a nation's economic performance.

Multiplier

A factor that quantifies the change in economic output resulting from a change in fiscal or monetary input.

MPC

Marginal Propensity to Consume, a measure of how much consumption changes with a change in income.