If you are exposed to H1N1 09 Swine Flu and then days later get vaccinated will you get the flu?

Answer 1

It is possible that if you are exposed to the Swine Flu H1N1/09 virus before getting vaccinated for the same flu virus, you could still get the flu. It will not be because you took the vaccine that you would have the flu, however, it would only be because you did not get the vaccine in time to prevent the flu from the prior exposure. The vaccine does not work as soon as you get it. It can take 8 to 10 days for the body to develop the immunity in children over ten and adults who are otherwise healthy (longer in younger children and infants and in those who have compromised immune systems). So, since the incubation period for the swine flu is estimated to be around 4 days (most estimations are from 1 - 7 days), it is possible that you may get the flu from a prior exposure before the vaccine can be effective in protecting you.

Answer 2

Vaccinations work to give you immunity to Infectious Diseases by tricking your immune system into thinking you have the virus which makes it develop an immune response and make the antibodies you need to be immune. You can also get immunity by having had the infection. So, you should already be immune through both mechanisms, there would be no reason to get another vaccination.

If you had a swine flu vaccination and then got the diagnosis of swine flu, you did not get it because your vaccination wasn't good and you did not get it from the vaccination. You either had the flu before you got the vaccination but the symptoms had not yet shown up, or you caught the flu between the time of getting the shot and when you had achieved immunity from the shot (it usually takes a week or two with most flu infections to develop the immunity).