Today’s New York Times has a great article on viruses, inspired by writer Natalie Angier’s post-New Year’s Eve norovirus encounter.

In it she writes that viruses are:

infectious parasitic agents tiny enough to pass through a microfilter that would trap bacteria and other microbes, tiny enough to fit millions on board a single fleck of spit. All viruses have at their core compact genetic instructions for making more viruses, some of the booklets written in DNA, others in the related nucleic language of RNA. Our cells have the means to read either code, whether they ought to or not. Encasing the terse viral genomes are capsids, protective coats constructed of interlocking protein modules and decorated with some sort of docking device, a pleat of just the right shape to infiltrate a particular cell. Rhinoviruses dock onto receptors projecting from the cells of our nasal passages, while hepatitis viruses are shaped to exploit portholes on liver cells.

I’ve been a big fan of viruses for a long time.  I read a book in high school (Level 4: Virus Hunters of the CDC) which led me into molecular biology and genetics, where virology became my favourite undergraduate course. Angier succinctly summarizes why I think viruses are so cool:

They depend on our cells to manufacture every detail of their offspring, to print up new copies of the core instruction booklets, to fabricate the capsid jackets and to deliver those geometrically tidy newborn virions to fresh host shores. Through us, viruses can transcend mere chemistry and lay claim to biology.