1.   But those vaccines did nothing to stop free-floating virus.

2.   Cancer vaccines enhance the immune system not to prevent a disease, as do most vaccines, but to attack a tumor that already exists.

3.   In healthy adults, the vaccine did no apparent harm, and stimulated the body to make high levels of infection-fighting antibodies.

4.   She said she believes his approach could prolong life in the next century the way polio vaccines did in this one.

5.   The flu vaccine can do nothing to prevent anthrax, Fukuda said.

6.   But there are questions about whether the vaccine really does this.

7.   However, even if the vaccine works, many experts doubt it will stop infection cold the way most vaccines do.

8.   Scientists said it is far too soon to tell if the vaccine will actually do patients any good.

9.   Scientists said it is far too soon to tell if the vaccine will do patients any good.