Are there viruses that infect other viruses, rather than cells?
On the one hand, I know (at least, I think I know) that viruses need living cells to reproduce, so “infecting” another virus isn’t productive. On the other hand, I could see a weaker, simpler virus taking advantage of another virus’s ability to infect a cell by piggy-backing itself.
This isn’t answering your question, which is a good one because I can’t recall an answer off the top of my head. But in the topic of discussion I just wanted to add that there does exist the bacteriophage , a virus designed to “attack” bacteria.
I’m rather certain the answer is no. A virus is just a shell plus some DNA/RNA. If a virus infected another virus, all it would have achieved would be changing shells. Plus there is no room for more DNA in a typical virus shell.
Actually, in a sense, what you talk about does exist. Satellites are viruses which are further dependent on other “helper” viruses to infect a common host. Here’s another good source, though one a bit less authoritative. One variety are the satellite viruses, which include genes for their own protein capsule, but are still dependent on that helper to infect and reproduce within a host. Then there are satellite nucleic acids, which are simply short lengths of DNA or RNA that literally hitch a ride in the protein coat of its helper virus – probably the closest to what you are asking about.
The impression that I get is that in some cases, satellites could be considered parasites, but in others they confer an advantage to their helper. Things get really ambiguous at this level of life.
