Virology 101

A new class is starting at virology blog: Virology 101.

I began this blog in 2004, to give back what I’ve learned from studying viruses for 30+ years. I’ve written many posts on basic virology, but they tend to disappear with time. To remedy this problem, I’ve collected all these posts with links back to the original article, arranged by topic. They are typically short and easy to read; if you start from the top, soon you will have a good basic understanding of virology.

I’ve also included relevant episodes of the podcast TWiV, where we discuss basic virology about once a month.

For the more adventurous, see the video podcasts from my Columbia University virology course, W3310. This course is taught in the spring semester each year. I’ve also included some of my other lectures to medical and undergraduate students.

If you are specifically interested in influenza virus, there is always Influenza 101.

Class will always be in session: there is much more to come.

With this virology course you also get access to a virology professor. If you have any questions, send them to

Basic Background Information

What is a virus? (W3301)

Introduction to virology I and II (Medical school lecture)

What is a virus?

Are viruses living?

Discovery of viruses

What color is a virus?

How viruses are classified

Virus classification (TWiV 43)

Simplifying virus classification: The Baltimore system

Viral genomes (TWiV 49)

Genomes and genetics (W3310)

The infectious cycle lecture (W3310)

Measurement (also see the virology toolbox)

Detecting viruses: The plaque assay

How many viruses are needed to form a plaque?

Measurement of viruses by end-point dilution assay

Multiplicity of Infection

The western blot

Detection of antigens or antibodies by ELISA

Detecting viral proteins in infected cells or tissues by immunostaining

Virus Structure

Virus structure (TWiV 39)

Virus structure (W3310)

Attachment and Entry into Cells

Virus entry into cells (TWiV 46)

Attachment and entry (W3310)

Nucleic Acid Synthesis

RNA synthesis (W3310)

Making viral RNA (TWiV 60)

Making viral DNA (TWiV 96)

Making viral DNA II (TWiV 106)

Genome replication of DNA viruses (W3310)

Transcription (TWiV 162)

Reverse transcription (W3310)

Reverse transcription (TWiV 66)

Transcription and RNA processing (W3310)

Processing viral RNA (TWiV 216)

Protein synthesis

Translation (W3310)

Virion Assembly

Assembly (W3310)

Pathogenesis and Immunity

Infection Basics (W3310)

Host Defense (W3310)

Virus-Host Interactions (W3310)

Viral Pathogenesis (Medical school lecture)

Acute Infections (W3310)

Antigenic variation explains recurring acute infections

HIV Pathogenesis (W3310)
Transformation and Oncogenesis (W3310)

Innate sensors of DNA

Immunopathology: Too much of a good thing

Innate immune defenses

The inflammatory response

Adaptive immune defenses

Adaptive immune defenses: Antibodies

Virus neutralization by antibodies

The complement system

C1q and the collectins

Natural antibody protects against viral infection

Prevention and Control

Vaccines (W3310)

Antiviral Drugs (W3310)

Tamiflu-resistant pandemic influenza H1N1 virus selected by prophylaxis

Vaccines lecture (Immunology course, different from W3310 version)

Discussion of new HCV antiviral on Futures in Biotech 60
(download the HCV part of the discussion here)

Evolution and Emergence

Viral Evolution (W3310)

Emerging Viruses (W3310)

Viruses and the tree of life

The abundant and diverse viruses of the seas

Chikungunya: An exotic virus on the move

Lujo virus, a new hemorrhagic fever virus from Southern Africa

The error-prone ways of RNA synthesis

The quasispecies concept

Viral quasispecies and bottlenecks

The number of possible viral variants

Pushing viruses over the error threshold

Increased fidelity reduces viral fitness

Why don’t DNA based organisms discard error repair?

The trajectory of evolution

Virulence: A positive or negative trait for evolution?

Topics that don’t fit anywhere else

Unusual Infectious Agents (W3310)