- Poliovirus
- Herpes simplex virus
- Retrovirus
- Norovirus
- Based on viral size
- Based on replication strategy
- Based on virulence
- Based on capsid shape
- Infect bacteria only
- Infect plants
- Are spread via arthropods
- Are transmitted from animals to humans
- Influenza virus
- Hepatitis B virus
- Poxvirus
- Herpes simplex virus
