While there is a theoretical risk that a person inoculated with a live viral vaccine such as the live, attenuated influenza vaccine (LAIV; the nasal spray) can transfer the vaccine virus to a close contact this has rarely been demonstrated. In that reported incident the person who became infected, did not become ill. The LAIV is attenuated, meaning it does not cause disease and it is cold-adapted meaning it cannot replicate at body temperature. It only can replicate in the mucosa (lining) of the nose, therefore making it unlikely to cause disease. in addition a person receiving the LAIV sheds smaller amounts of virus and for a shorter duration than with wild-type (naturally occurring) virus. Therefore it is considered safe to give it to someone who is living in the same household with a person with a weakened immune system.