Question

viral infections can be prevented by vaccines, which are

Answer 1

Vaccines prepare your body for a possible run in with a virus. By exposing your body to the viral strain before you actually get the virus allows your body to produce a much stronger immune response when it actually does get the virus.

When you are injected with the vaccine, your body will first assess the foreign molecule with antigens, and then the antigens will signal the production of antibodies to fight off any future infection. It's kind of like our body learning from experience. If we got the virus once, it's possible we could get it again... so our body prepares for that. This is why our immune response is very slow when we get a disease that we haven't been vaccinated for, or have never been exposed to before. Our bodies have to take the time to assess the foreign disease, and make antibodies for it, which takes time.

If we are subjected to just a small amount of the virus before we contract it, it is essentially preparing our bodies so that our immune response is much stronger than it would be without ever having been exposed to it.
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