What happens if a person gets infected with just a single virion?

Question

Like if just one viral particle gets into your system, what’s more likely to happen: it proliferates undetected and cause an infection, or the immune system eliminates it before it can do so?

In: 164

Answer 1

Nothing happens really. A certain viral load (minimal infective dose I think is the more correct phrase) needs to be met usually. No idea if one virion can ever actually meet that though–pretty unlikely, but possible. Typically some part of the immune system will catch a few strays before they can do anything–be it mucus, hairs, t-cells, or what have you.

edit: clarification