1.   After release, viruses remain inactive until they come into contact with and infect another cell.

2.   Viral infectiousness is defined as the ability of a virus to enter and infect a cell in the target host.

3.   A newer anti-HIV drug called pyridinone caused HIV to mutate into a form which could not reproduce or infect new cells.

4.   They are small and can only carry a small amount of human DNA, and only infect dividing cells.

5.   The gene was transferred by splicing it into the DNA of a bacterium which naturally infects plant cells.

6.   And a protease inhibitor, which blocks the protease enzyme needed for the HIV virus to infect other cells, may not even be necessary.

7.   As a result, they can survive a form of malaria that infects the cell only if it can attach to Duffy.

8.   At first glance, it seemed that the shape of the protein molecule would actually prevent a virus from infecting a cell.

9.   Because scientists do not have a full understanding of how HIV infects cells, clarifying the mechanism by which SLPI blocks infection could have broader importance.

10.   A virus only shows real signs of life after it has infected a cell.