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The second part of the HIV series covers everything that happened after the virus was discovered: the intense stigma of the early years, the US government's years of inaction under Reagan and the activism that drove the development of treatments and public awareness. Florian Krammer explains how a near-certain death sentence became a manageable chronic condition, what PrEP is and how it works, and how a handful of people (the "Berlin patients") were actually cured of HIV. The episode closes with the current situation: why UNAIDS estimates that the withdrawal of US funding could lead to millions of additional infections...

The first of a two-part series on HIV starts with the virus itself and its history. Florian Krammer explains why HIV is one of the most cunning viruses we know: it infects the very cells of the immune system, permanently writes itself into our DNA, and hides from immune detection.

To wrap up the hepatitis series, this episode covers the final letter: hepatitis E. A virus that's harmless for most people, often going completely unnoticed, but can be life-threatening for pregnant women and those with weakened immune systems.

An Ebola outbreak is currently unfolding in the Democratic Republic of Congo — caused not by the well-known Ebola Zaire, but by Bundibugyo Ebola virus, a species for which no licensed vaccines or proven treatments exist. This episode covers the basics of Ebola viruses, how they spread, why they cause such severe disease, and what makes this particular outbreak so difficult to contain: it was detected late, it's happening in an active conflict zone, US support has largely been withdrawn, and the medical countermeasures simply aren't there yet. A global pandemic is unlikely given the transmission routes, but for the...

We all inhale mold spores every day — for most people, that's not a problem. But for those with a weakened immune system or pre-existing lung conditions, it can become life-threatening. In this episode, Florian talks with Prof. Helmut Salzer, Head of Infectious Diseases and Tropical Medicine at Kepler University Hospital in Linz, about Aspergillus and the three forms of aspergillosis: invasive, chronic, and allergic. Around four million people are affected worldwide every year, with more deaths than influenza causes annually. Yet the disease remains largely under the radar.

Andes virus is the only known hantavirus that can spread from person to person and that's exactly what makes the current outbreak on the cruise ship MV Hondius so unprecedented.

Before SARS-CoV-2, there was SARS-CoV-1 - a closely related coronavirus that caused a serious outbreak in 2002–2003 with a case fatality rate of around 10%. Unlike its successor, SARS-CoV-1 only became transmissible after symptoms appeared, which made it possible to identify and isolate infected people even without PCR tests. The virus spread from China to Hong Kong, Canada, Singapore, and Vietnam via superspreader events before a global effort managed to contain it by June 2003. The likely origin: horseshoe bats at wet markets in Guangdong, with palm civets and raccoon dogs as intermediate hosts.

A virus previously known only from shrimp farms and fish is now linked to a serious eye disease in humans. Covert Mortality Nodavirus (CMNV) has been detected in over half of fish samples and nearly two-thirds of crab samples tested at markets and a new study in Nature Microbiology (March 2026) connects it to a persistent form of viral uveitis that can permanently damage the optic nerve and lead to severe vision loss.

Rhinoviruses are a highly diverse group of RNA viruses responsible for about half of all common cold infections and are something most people encounter multiple times in their lives. In this episode, Florian Krammer explains the biology of these non-enveloped viruses, their large number of strains, and how they infect the upper respiratory tract.

Lassa virus is a rodent-borne arenavirus that causes Lassa fever, a hemorrhagic disease endemic in West Africa with hundreds of thousands of infections each year. In this episode, Florian Krammer explains the biology of this ambisense RNA virus, including its segmented genome and how it interacts with the immune system. The discussion covers transmission through contact with infected rodents, human-to-human spread via bodily fluids, and typical symptoms ranging from mild flu-like illness to severe disease with bleeding, organ failure, and neurological complications.