Can the H1N1 live flu vaccine virus be transmitted to other people?
Yes, very rarely the vaccine virus can be transmitted to other people through respiratory droplets the same way that the “wild” influenza virus is transmitted. This is called “shedding”. However, the virus in the live H1N1 vaccine is shed in small quantities so transmission is very rare. Also, the vaccinated person is shedding the weakened, cold-adapted flu virus that doesn’t cause influenza illness.
