There are more than 200 known viral diseases of which only very few are treatable with current antiviral drugs. Broadly applicable antivirals - similar to broad-spectrum antibiotics - would have a dramatic impact on human lives. We at capsitec are establishing a completely new class of broad-spectrum antivirals. Our antiviral platform entails engulfing and neutralizing viral pathogens within de novo designed macromolecular shells. The encapsulation prevents the viruses mechanically from interacting with host cells, which hinders virus reproduction. Our concept constitutes the first broad-spectrum antiviral platform that has the potential to help combat many different virus infections.