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 …
A network of ~150 laboratories in the United States participate in virological surveillance for influenza. The results of these analyses are publicly available, and provide extremely interesting characterization of the pandemic spread of the new H1N1 strain. During week 22, 6,664 samples were submitted for testing, of which 2,681 were positive for influenza virus. Of …
WHO reports that as of 15 June 2009, 76 countries have officially reported 35, 928 cases of influenza A(H1N1) infection, including 163 deaths. These numbers can be used to calculate a case fatality ratio (CFR) of 0.45%. Is this number an accurate indication of the lethality of influenza? Determining how many people die from influenza …
Viruses are known to evade the early, or innate, host defenses by interfering with the sensing of infection, production of IFN, and synthesis and activity of ISGs. Today we’ll examine the evidence that the function of one or more ISGs is blocked in poliovirus-infected cells. When IFN is added to the medium of cultured cells, hundreds of …
On episode #36 of the podcast “This Week in Virology”, Vincent, Alan, Dick, and Hamish Young discuss the 2009 influenza pandemic, first 2009 H1N1 vaccine, hunting mosquitoes with midges, vaccine-associated polio in India, and adenoviruses. [powerpress url=”http://traffic.libsyn.com/twiv/TWiV036.mp3″] Click the arrow above to play, or right-click to download TWiV #36 or subscribe in iTunes or byemail.
Host defense mechanisms are imperfect because the genomes of every known virus encodes proteins that can block nearly every step of the immune response. For every host defense, there is a viral offense. Let’s consider the different ways that viruses are known to evade the early, or innate, host defenses. The illustration depicts in a …
