Nidovirus is a family of viruses known for their unique structure and genetic makeup. They are characterized by a single-stranded RNA genome and are primarily found in animals, including birds and mammals. Some well-known members of this family include Coronaviruses, which have gained significant attention due to their role in human diseases like COVID-19. These viruses can cause various illnesses, ranging from mild respiratory infections to more severe diseases. Nidoviruses replicate in the host's cells, leading to the production of new viral particles. Understanding nidoviruses is crucial for developing vaccines and treatments to combat the diseases they cause.