Both the Finnish and the U.S. bird flu vaccines are made by CSL Seqirus but are different vaccines. In the summer, U.S. officials stockpiled 4.8 million doses of the vaccine that officials said was effective against circulating H5N1 strains. In October, the U.S. issued a $72 million grant to three manufacturers to double the nation's stockpile.

The highly contagious H5N1 bird flu virus may be spreading through the air under certain conditions, according to a new study from the Czech Republic. Government veterinarians made the discovery while investigating a mysterious outbreak at a highly secured chicken farm last February.