Updated

In a brief Rose Garden ceremony Wednesday, President Bush signed into law a $4.6 billion bioterrorism bill that is aimed at strengthening the nation's defenses against a bioterrorist attack.

"We must be better prepared to prevent, identify and respond and this bill I am signing today will help a lot in this essential effort," Bush told an audience that included Secretary of Health and Human Services Tommy Thompson, Homeland Security Chief Tom Ridge, and bill co-sponsors Sens. Ted Kennedy, D-Mass., and Bill Frist, R-Tenn., the Senate's only doctor.

The bill provides $640 million to develop a smallpox vaccine and creates better methods for the detection and prevention of tainted foods entering ports. It tracks biological materials, and increases assistance to health care officials who are most frequently on the frontlines of a bioterror attack.

The measure also would expand availability of potassium iodide for communities near nuclear plants to treat radiation poisoning in the event of a terrorist attack.

"Biological attacks can be carried out quietly. Our health care professionals are likely to be the first to recognize that there has been an attack. The speed with which they detect and respond to a threat to public health can be the difference between containment and catastrophe," Bush said.

The bill, approved in the House and Senate by overwhelming majorities last month, provides $1.6 billion in grants to help states and localities improve their response to a bioterror attack.

The Public Health Security and Bioterrorism Response Act also:

• strengthens protections of the nation's food and water supply;

• increases the nation's stockpile of vaccines and medications to protect against biological and chemical weapons;

• places stronger controls on laboratories and universities that "possess dangerous pathogens" and creates a national database to track such pathogens;

• provides $300 million to upgrade laboratories and equipment at the Centers for Disease Control and Prevention;

• provides grants to colleges and universities "that have food and agriculture science programs to review and assess security standards and practices"; and

• develops "rapid detection field kits to detect biological threats to animals and plants."

The bill is an outgrowth of Congress' own bioterrorism attack, which occurred just one month after the Sept. 11 attacks. In October, anthrax-contaminated letters arrived in the offices of Senate Majority Leader Tom Daschle, D-S.D., and Senate Judiciary Committee Chairman Patrick Leahy, D-Vt.

Mail Service to Capitol Hill stopped for six weeks as hundreds of employees were put on antibiotics. Anthrax was also sent to the Federal Reserve, the World Bank and traces appeared in mail destined for the White House, the State Department and foreign embassies. Five people, including two postal workers, died from exposure, but no one was arrested.