1962
A study of anthrax vaccine involving goat-hair mill workers is published.

1970
The Michigan Department of Public Health receives a license for anthrax vaccine. Most users work at federal biological weapons labs.

1991
About 150,000 U.S. troops deployed for the Persian Gulf War get anthrax shots, the first widespread use of the vaccine.

1997
Defense Secretary William Cohen orders the beginning of mandatory anthrax vaccination. More than 450 troops refuse to take it in following years.

1998
BioPort Corp. is formed. The company buys the anthrax vaccine plant and license rights from Michigan.

2004
A U.S. district judge rules the vaccine was not properly licensed for protection against inhaled anthrax and says troops can't be forced to take it until it's properly licensed.

2005
The Pentagon begins the voluntary anthrax vaccination program. It appeals the ruling that made the vaccinations voluntary.

The Daily Press, Hampton Roads, Virginia