What phenomenon occurs when two different strains of viruses co-infect the same host cell and interact during replication?

The phenomenon where two different strains of viruses co-infect the same host cell and interact during replication is known as recombination. In this process, genetic material from the two viral strains can be exchanged, leading to the creation of new viral genomes that may have different properties than the original strains. This is particularly significant in the context of RNA viruses, where recombination can lead to increased genetic diversity and potentially new viral phenotypes.

Recombination can result in viruses that might have enhanced virulence, altered host range, or differing responses to existing vaccines and antiviral therapies. This genetic interaction allows for rapid evolution in viral populations, which is a crucial factor in the emergence of new viral strains in diseases affecting humans and animals.

This process is distinct from other viral processes like mutation, where changes occur in the viral genome due to errors during replication, or lysis, where the host cell breaks down and releases new viral particles. Viral fusion, while relevant in the context of how viruses enter host cells, does not pertain to the interaction of different virus strains at the replication stage.