The main difference between (+)-sense and (-)-sense ssRNA viruses lies in how they use their genetic material for replication 🧬. (+)-sense ssRNA viruses, like Poliovirus 🦠, can directly serve as mRNA for protein synthesis in the host cell. In contrast, (-)-sense ssRNA viruses, such as the Rabies virus 🧟♂️, need to convert their RNA into a (+)-sense RNA before the cell can use it to make proteins. Think of (+)-sense RNA as a “ready-to-use” message, while (-)-sense RNA requires a “translation” step first 🔄.