Efficacy of a 3C-like protease inhibitor in treating various forms of acquired feline infectious peritonitis

Pedersen, Niels C; Kim, Yunjeong; Liu, Hongwei; Galasiti Kankanamalage, Anushka C; Eckstrand, Chrissy; Groutas, William C; Bannasch, Michael; Meadows, Juliana M; Chang, Kyeong-Ok

This was the first attempt to use a targeted antiviral drug against a systemic and highly fatal disease of veterinary importance. Although no specific antiviral drugs are yet available for coronavirus infections in people or animals, antiviral drugs for other viral infections of people, such as HCV and HIV-1, have been developed for treatment and the use of these drugs provided a sound base for their application to animal diseases such as FIP. HCV mainly infects liver cells, causing persistent viral infection in a majority of people. However, only about 20-30% of them develop liver diseases in 20-30 years. HCV infection can be cleared with non-specific antiviral treatment (interferon and ribavirin) over 6-12 months in about half of patients, and recent introduction of directacting antiviral drugs of 3-6 months, duration considerably increased the cure rate to more than 90%. 2 HIV infection in people leads to a prolonged asymptomatic state and eventually to advanced HIV disease. HIV-1 infects T cells and macrophges and survives in a latent state. More than 30 antiretroviral drugs, most of them used in combinations of two or more drugs, have been successfully used to reduce viral load to undetectable levels in the blood of HIV/AIDS patients. However, the virus rebounds on discontinuation of antiviral treatment, necessitating life-long antiviral treatment. Dissemination of virus to the brain, which is mainly mediated by virus-infected macrophages, and subsequent development of neurologic disease occurs in more than 50% of HIV infections. 17 Therefore, neurologic impairment still remains an important problem even in this antiviral treatment era. These precedents of antiviral treatment of HCV and HIV-1 infections show that treatment outcome (viral clearance vs viral persistence), treatment duration (finite vs continous) and the presence of neurologic sequelae are greatly influenced by viral pathogenesis.