1.   Along the way, some experimental vaccines disappear.

2.   Also, the experimental Wistar vaccine had been given in Poland and Sweden, and AIDS was not reported there in the critical years.

3.   An experimental AIDS vaccine may be a particularly tough sell to some of the hardest-hit populations, including young gay men and blacks.

4.   Before working with rubella, Meyer tested an experimental vaccine against red measles, or rubeola, in West African nations hit hard by an epidemic.

5.   A number of experimental vaccines are being tested in the United States, Thailand and elsewhere.

6.   But other experts say that full-scale tests should be conducted only when laboratory and animal research shows a solid scientific understanding of how an experimental vaccine works.

7.   Currently, nearly all experimental AIDS vaccines are targeted against the B-subtype, which is still predominant in North America.

8.   Dr. Ira Wolmer, a cardiologist, underwent three bone marrow transplants and tried an experimental vaccine, his wife said, but nothing worked.

9.   Earlier guidelines, intended to prevent exploitation, called for testing any experimental AIDS vaccine in the country where it was made before testing it in a developing country.

10.   For the experimental vaccine, Letvin and his team spliced together DNA from both a human HIV virus and a monkey form of the virus.