MedImmune's nasal vaccine could be a strong weapon during this upcoming flu season in preventing a greater nationwide outbreak of the swine flu.

MedImmune, which already manufactures the nasal spray mist vaccine, Flu Mist, for seasonal flu viruses, says it is on track to produce about five times as much swine flu vaccine as the company had expected. MedImmune has such an overload of vaccine doses that it has run out of nasal spray devices.

Because the vaccine uses a live -- but weakened -- virus, MedImmune uses a different viral strain than the makers of other flu shots, which contain an inactivated virus. The live virus gives MedImmune an edge over its competitors because the company's strain of virus grows quicker than the inactivated viruses, allowing for a faster rate of production.

Safety concerns regarding the live virus exist however. The vaccine might not be appropriate for patients with weaker immune systems. 

Get an update on what our nation is doing to prevent a record-breaking flu season by reading the full article here: http://www.nytimes.com/2009/07/31/business/31flumist.html?_r=1&ref=health