Basically, a helical capsid is like a spiral-shaped protein shell. Imagine a tube that’s twisted — that’s the structure it forms around the viral genome. Viruses with this kind of capsid include things like the Tobacco Mosaic Virus (TMV), which affects plants. On the other hand, an icosahedral capsid is more like a 3D shape with 20 triangular faces, kinda like a soccer ball. A good example of a virus with this shape would be the Adenovirus, which causes respiratory illnesses. Both capsid types protect the virus’s genetic material, but they do so in different ways!
