Question

1. 13. live-virus vaccines are made from?

a. dead pathogens
b. pathogens grown in laboratories
c. parasites
d. bacteria

Explanation:

To determine the correct answer, we analyze each option:

• Option a: Dead pathogens are used in inactivated vaccines, not live - virus vaccines. So a is incorrect.
• Option b: Live - virus vaccines are made from pathogens (viruses) that are grown in laboratories and then attenuated (weakened) so that they can still stimulate an immune response but do not cause the severe disease. This matches the nature of live - virus vaccines.
• Option c: Live - virus vaccines are related to viruses, not parasites. So c is incorrect.
• Option d: Live - virus vaccines are about viruses, not bacteria. So d is incorrect.

Answer:

b. Pathogens grown in laboratories