Some viruses, called satellites, can replicate only within cells that have already been infected by another virus.

All viruses replicate themselves, but some merely leave messages on the screen.

Certain viruses can replicate in brain cells and cross synapses.

The virus replicates, or copies itself, and takes over the functions of the cell.

After letting the viruses replicate, the scientists took a small sample to start a new colony.

And if the virus couldn't replicate, it would be gone in a single generation.

This made the virus replicate at a fast rate.

In human trials, testing is done to make sure the viruses cannot replicate themselves.

That's an indication, in one case, that the virus does not replicate very well.

The virus may replicate in the mite but this is not certain.