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 World Health Organization has declared that the world is now at the start of an influenza pandemic. WHO Director-General Dr. Margaret Chan said today: I have conferred with leading influenza experts, virologists, and public health officials. In line with procedures set out in the International Health Regulations, I have ...

Scientists and philosophers have long debated the trajectory of evolution. Some of the questions they consider include: is there a predictable direction for evolution, and if there is, what is the pathway? Are there evolutionary dead ends? Viruses are excellent subjects for the study of evolution: they have short generation ...

With just 141 confirmed deaths so far, an interesting question is whether the 2009 H1N1 influenza virus could mutate into something more lethal ("How a Mild Virus Might Turn Vicious"). Of course it could - but is it beneficial for the virus? A fundamental principle of viral evolution is that ...

While perusing the cleaning items at the supermarket last night, I spotted the words 'Kills Flu Virus' on a bottle of toilet bowl cleaner. Do toilets play a role in transmission of influenza? Influenza is an infection of the respiratory tract. The virus enters the tract in aerosols or by ...