Scanning electron micrograph of epithelia lining the airways.

Andreas Wack : Immunoregulation Laboratory

We are finding out why infection with influenza (flu) viruses causes only mild symptoms in some people, while in others the infection can be severe and even deadly.

Every year the influenza (flu) virus causes 3 to 5 million cases of severe illness around the world, and it is responsible for up to 650,000 deaths. It is not clear why flu is sometimes a serious illness but rather mild in other individuals.

The virus damages the delicate tissue in the lungs during infection, and the body’s immune response aimed to control the virus also causes damage. Often, the severity of flu depends more on the patient’s immune response than on the virulence of the virus. One consequence of the lung damage is that the lung becomes more susceptible to bacterial infection.

We are investigating what happens in the lungs when flu viruses and the immune response clash and which factors determine how severe the infection is. We also study how flu virus and bacteria team up to cause life-threatening infections, and why this happens in some people and not others. We are studying mouse and human lung cells grown in the lab, focusing on the earliest events that happen when viruses.

We want to know how these infectious agents interact with the molecular machinery inside cells, and how the immune system recognises and responds to the attack. And we are looking at how other factors, such as air pollution, may make flu worse.

We are using our findings to develop new ideas to prevent or treat flu and related bacterial infections, which could save many lives.