Question

What cells respond to an invading viruses that the body has already been vaccinated against?

Answer 1

Answer:

The B lymphocytes (antibodies) and the T lymphocytes.

Explanation:

Imitating an infection is the process by which a vaccination develops immunity. However, this kind of infection never leads to illness, it does make the immune system to generate B lymphocytes and T lymphocytes. The produced B and T lymphocytes are the memory cells, which remembers to fight against the disease in the future.

Answer 2

Vaccines help develop immunity by imitating an infection.  but it does cause the immune system to produce T-lymphocytes and antibodies. Sometimes, after getting a vaccine, the imitation infection can cause minor symptoms, such as fever.