The virus is one of the smallest enveloped animal viruses. Aphids are often infected by bacteria, viruses, and fungi. Grasshoppers are affected by diseases caused by bacteria, viruses, fungi and protozoa. Mosquitoes can act as vectors for many disease-causing viruses and parasites. They are active against bacteria and some viruses, fungi, and protozoa. The air transports viruses and other pathogens. Worms are more infectious than traditional viruses. Fungi produce compounds that inhibit viruses and cancer cells. Ozone is more effective than chlorine in destroying viruses and bacteria. Some are pests or vectors of plant viruses and phytoplasmas. The Sabin vaccine is an oral vaccine containing weakened forms of strains of polio viruses. It contains antibodies against many viruses. Chloroquine has antiviral effects against some viruses. Rivers wanted to show the link between viruses and diseases. Many human oncogenic viruses have been identified.