The second RNA segment of the influenza virus genome encodes the PB1 protein – part of the viral RNA polymerase – and, in some strains, a second protein called PB1-F2. The latter protein is believed to be an important determinant of influenza virus virulence. The absence of a full-length PB1-F2 protein has been suggested as …
There are two glycoproteins embedded in the influenza viral membrane: the hemagglutinin (HA) and neuraminidase (NA). The NA, shown in yellow in the illustration, is an enzyme that removes sialic acids from the surface of the cell, so that newly formed virions can be released. The NA protein is composed of a box-like head attached …
Many virologists, including myself, believe that the threat of avian H5N1 influenza is not only overestimated, but also distracts from serious consideration of other potential pandemic strains. In early 2005 I wrote about this problem (“Should we worry about avian influenza?) and suggested that we should pay attention to H2N2 strains as a potential pandemic …
As we discussed previously, attachment of all influenza A virus strains to cells requires sialic acids. However, there are a number of chemically different forms of sialic acids, and influenza virus strains vary in their affinity for them. These differences may determine which animal species can be infected. In the example shown below, sialic acid …
Influenza virus attachment to cells: role of different sialic acids Read More »
On episode #28 of the podcast “This Week in Virology”, Vincent, Dick, Alan, and Eric F. Donaldson discuss a new test for influenza H5N1, poliovirus in Minnesota, Koala retrovirus, batteries made from viruses, and SARS. Click the arrow above to play, or right-click to download TWiV #28 or subscribe in iTunes or by email.
Last week the US Food and Drug Administration approved a rapid test for determining whether a person is infected with an H5N1 subtype of influenza virus. Why is it better than previously available influenza diagnostic assays? The format of the new assay, according to its developer, ArborVita, “is the familiar lateral-flow rapid antigen assay”. This …
