11.   So far, Taubenberger and his colleagues have sequenced half the viral genes.

12.   When cellular genes were turned on, so were the viral genes.

13.   Doctors say that trying to understand how well drugs will work by analyzing viral genes can be daunting when the virus is resistant to several drugs.

14.   Four out of five animals that had gotten one viral gene and three of five that had gotten another were protected.

15.   In test-tube studies, it seems accurate at spotting just four copies of a viral gene in blood.

16.   In the first attempt to fight AIDS with gene therapy, scientists said Monday they have fired fake viral genes into the blood cells of three infected volunteers.

17.   One of these genes, called rev, pulls together the newly manufactured viral genes so they can be packaged into more viruses.

18.   The Yerkes version combines viral genes with a genetically engineered smallpox vaccine.