In temperate climates, influenza displays distinct seasonality: infections mainly occur from November through March in the northern hemisphere, and from May to September in the southern hemisphere. The results of experiments in guinea pigs have revealed that aerosol transmission of influenza virus is most efficient in cold and dry conditions, and completely blocked at warm …
Although many viruses are classified into individual families based on a variety of physical and biological criteria, they may also be placed in groups according to the type of genome in the virion. Over 30 years ago virologist David Baltimore devised an alternative classification scheme that takes into account the nature of the viral nucleic …
Simplifying virus classification: The Baltimore system Read More »
Recently while driving north on the New York State Thruway I passed the exit for the town of Coxsackie, NY (population 8,884). I grabbed my camera and photographed the exit sign, and reminded myself to write about the virus named after this small town. In the summer of 1947 there were several small outbreaks of …
For the first 60 years of virus discovery, there was no system for classifying viruses. Consequently viruses were named haphazardly, a practice that continues today. Vertebrate viruses may be named according to the associated diseases (poliovirus, rabies), the type of disease caused (murine leukemia virus), or the sites in the body affected or from which …
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 …
The antibody response is crucial for preventing many viral infections and may also contribute to resolution of infection. When a vertebrate is infected with a virus, antibodies are produced against many epitopes on multiple virus proteins. A subset of these antibodies can block virus infection by a process that is called neutralization. Antibodies can neutralize viral infectivity …
