When antiviral drugs are widely used, resistance usually follows. Viruses mutate, treatments lose strength, and scientists scramble to adapt. That pattern has been seen with influenza, HIV, and many other infections. When the anti-viral drug Paxlovid was rolled out globally to treat COVID-19, many experts expected that the virus would eventually evolve ways to evade it. But several years on, meaningful resistance has not taken hold. In two closely connected studies, Dr Brent Iverson and colleagues set out to understand why. Their findings suggest that the virus may be more constrained than many had assumed – and that those constraints are helping Paxlovid remain effective.

Pulmonary fibrosis is a devastating disease in which lung tissue becomes scarred and stiff, making it harder to breathe. The outlook for patients remains poor, with many surviving only a few years after diagnosis. Current treatments can slow the damage, but they cannot reverse it. New research by the team of Prof. Christian Bär and Dr. Shambhabi Chatterjee of Hannover Medical School and their colleagues explore a promising alternative – one that works at the level of our cells’ biological ‘aging clock’.

Electronic cigarettes have been marketed as a safer alternative to traditional tobacco, but a growing body of research is painting a more troubling picture. Two studies from North Carolina Central University, conducted by Rob Onyenwoke and colleagues, suggest that vaping doesn’t just harm the lungs on its own – it may also make them far more vulnerable when infection strikes.