This week’s pop quiz involves analysis of an AFP news article entitled “US company makes first batch of swine flu vaccine“. The article reports that Protein Sciences has been awarded a contract from the US Department of Health and Human Services to produce a vaccine by synthesizing the viral HA protein in insect cells. Here …
The influenza virus hemagglutinin (HA) is the viral protein that attaches to cell receptors. The HA also plays an important role in the release of the viral RNA into the cell, by causing fusion of viral and cellular membranes. HA must be cleaved by cellular proteases to be active as a fusion protein. The HA …
Influenza HA cleavage is required for infectivity Read More »
Readers of virology blog have no doubt seen news reports that a Brazilian influenza isolate called A/Sao Paulo/1454/2009 (H1N1) is novel strain with mutations that enable it to infect new hosts. Here is one example of such a report, from The Australian: Brazilian scientists have identified a new strain of the H1N1 virus after examining …
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 …
The microneutralization assay is another technique used by the Centers for Disease Control and Prevention to determine that some adults have serum cross-reactive antibodies to the new influenza H1N1 virus. Let’s explore how this assay works. Viral replication is often studied in the laboratory by infecting cells that are grown in plastic dishes or flasks, …
Centers for Disease Control and Prevention have determined that some adults have serum cross-reactive antibodies to the new influenza H1N1 virus. One of the techniques used to reach this conclusion is the hemagglutination inhibition (HI) assay. How does this assay work? To understand the HI assay, we must discuss the hemagglutination assay. Influenza virus particles …
