Influenza 101

Soon after the new influenza H1N1 strain emerged in April 2009, I began a series of blog posts on basic aspects of influenza virus replication and pathogenesis. The goal of this series is to provide information that will allow everyone to better understand the events surrounding emergence and spread of the new pandemic strain.

Unfortunately blog posts tend to become invisible after a certain period of time, which does not befit educational material. Therefore I have made a list of these articles, with links, to make it easier for everyone to take Influenza 101.

Class is still in session.


Structure of Influenza virus

Influenza virus RNA genome

The A, B, and C of influenza virus

The neuraminidase of influenza virus

Influenza virus RNA: Translation into protein

Entry into Cells

Influenza virus attachment to cells

Influenza virus attachment to cells: role of different sialic acids

Cutting through mucus with the influenza virus neuraminidase

Release of influenza viral RNA into cells

Influenza HA cleavage is required for infectivity

RNA Synthesis

Influenza viral RNA synthesis

The error-prone ways of RNA synthesis

The quasispecies concept

Viral quasispecies and bottlenecks


Assembly of influenza virus

Packaging of the segmented influenza RNA genome

Reassortment of the influenza virus genome

Influenza virus reassortment, then and now

The neuraminidase of influenza virus


David and Goliath: How one cytokine may take down influenza

Gut microbes influenza defense against influenza

The D225G change in 2009 H1N1 influenza virus

It’s not easy to make the 2009 H1N1 influenza virus a killer

Influenza virus transmission

Viruses and the respiratory tract
How many people die from influenza?
Seasonality of influenza
Innate immune defenses
The inflammatory response

Adaptive immune defenses

Adaptive immune defenses: Antibodies

Virus neutralization by antibodies

Prevention and Control

How good is the influenza vaccine?

Pandemic influenza vaccine was too late in 2009

Universal influenza vaccines

Secondary changes allow spread of oseltamivir resistant influenza virus

Headless HA: Universal influenza vaccine?

Protection against 2009 influenza H1N1 by immunization with 1918-like and classical swine viruses

Reinfection with 2009 influenza H1N1

Influenza neuraminidase inhibitors work

Tamiflu-resistant pandemic influenza H1N1 virus selected by prophylaxis

Propagation and Measurement

Influenza virus growth in eggs

Influenza hemagglutination inhibition assay

Influenza microneutralization assay

Detecting viruses: the plaque assay

How many viruses are needed to form a plaque?

Measurement of viruses by end-point dilution assay