Question

Why is it difficult to make vaccines for viruses? (1 point)

O All known vaccine molecules must be tested to find the right one.
O All known viruses must be tested against new vaccines
O Viruses mutate to attack the vaccine molecules so new ones must be continually produced
O Vaccines are very small so it is difficult to determine if the molecule fits

Answer 1

All known vaccine molecules must be tested to find the right one.

Step-by-step explanation:

I took the test