We have spent over a week discussing the effects of polymerase error rates on viruses. RNA viruses have the highest error rates in nature, a property that is believed to benefit the viral population. For example, selective pressure from the immune system or antiviral drugs may lead to changes that ...

The capacity of RNA viruses to produce prodigious numbers of mutations is a powerful advantage. But remember that selection and survival must balance genetic fidelity and mutation rate. Many mutations are not compatible with viral replication. Consequently, if mutation rates are high, at some point accumulating base changes lead to ...

Here are answers to questions sent to virology blog about the new strain of influenza H1N1 that continues to spread globally. Q: Are you aware of efforts to make the virus strain nomenclature more informative? Understanding what segments/genes are related historically and sequence wise to what is confusing  using the ...

If you have been following our discussion of quasispecies here on virology blog, you might be wondering exactly how many possible variants there are for a viral genome. The answer is quite simple: for a genome N nucleotides in length, there are 4N possible variants, because there are 4 different ...

The influenza H1N1 outbreak in Mexico has been analyzed to provide information on the pandemic potential of the new virus strain. The estimates offer some insight into the transmissibility and severity of the virus but must be tempered with the understanding that there are still uncertainties about all aspects of ...