Response to exposure to a virus you've been vaccinated against

[feverdreams]

With Hep B as an example: how does the body respond to an exposure to a virus it has been vaccinated again?

So for example, you are exposed to Hep B, and the body is able to fight it off due to cell memory from the vaccination. Is there an infectious period during this time? Or is the virus contained too quickly in most cases?

[mkh9]

p.s. having said that. If you wait the amount of time the doctor or pharmacists recommends for the vaccine to work you will be fine.
mkh9

[mkh9]

I think you are asking if you have been vaccinated with something like Hepatitis B how soon are you protected from the vaccine? It takes three shots over a number of months. Once you have them all done I usually recommend that you get tested to see if you have the antibody to Hepatitis B. If you do you are protected anytime you are exposed. There is no lag period. I mean sure your immune system always takes a short time to determine if the object or virus is foreign to the body but that is just long term memory of the immune system not a time when you can get infected.  For a flu vaccine it takes about 2-4 weeks (depending on your immune system) to be protected. So it depends on the vaccine.
mkh9

[feverdreams]

Thanks for the response, though asking something slightly different. What I’m asking is, having been vaccinated for hepatitis B like most people were since the 80s, what happens if you were theoretically exposed to the virus years later? I know your body mounts a very competent response against it. But what I’m wondering is if there is possibly an infectious period before it is cleared, or if it never gets there because the body is able to handle it before then

[mkh9]

No.