A research collaboration is working to develop an antiviral, drug-like molecule that might treat a range of RNA viruses, from the infamous Zika and Ebola, to hepatitis C and type A influenza. Early tests of the molecule, whose broad-ranging antiviral capabilities were described in a December 2015 article in the Journal of Virology, have been sped up due to the public health crisis caused by the Zika outbreak.
The researchers received samples of the Zika virus that is now affecting 25 countries, especially Brazil and others in South America. The virus is mainly transmitted by Aedes mosquitoes, although its spread through blood transfusion and sexual contact has been reported. Usually, infection leads to relatively mild symptoms, such as fever, muscle and joint pain and skin rashes, that tend to resolve in two to seven days. But increasing evidence links Zika infection in pregnant women to babies born with microcephaly, a rare condition developed in utero or during infancy that results in the baby’s head being smaller than normal and has been associated with mental and physical disabilities. A great deal of research is being put into discovering if Zika is indeed the cause of rising incidences of microcephaly, although other causes are being investigated.
Michael Gale Jr., a University of Washington (UW) immunologist leading the project, is working with scientists at Kineta, the Seattle biotech company he co-founded, and the University of Texas at Galveston to create a broad-spectrum antiviral drug, KIN1400, that will treat Zika and other RNA viruses. The scientists have shown that KIN1400 can reduce the viral load in infected cells by triggering an innate immune response inside cells that eventually leads to the prevention of viral replication. Unpublished results show that the molecule is able to stop a 10-times lethal dose of H1N1 flu in mice and also protect against dengue, a disease that can be spread by the same mosquitoes that carry Zika.
Instead of targeting the virus itself, the drug works by stimulating the host’s immune response, disrupting a virus’ ability to mutate and evade the immune system. “The hope is to develop a pan-viral drug that would not have to be rejiggered to a specific virus,” Shawn Iadonato, Kineta’s chief scientific officer, said in a press release.
Researchers believe this drug, although too early to confirm, is promising for suppressing and controlling viral infection in already diagnosed patients. Future steps include UW approval of protocols to test the acquired Zika samples, and the development of accurate doses for testing in large animals and humans. This process can take from two to five years, and the researchers main goal is the proper response to, and control of, the next viral outbreak that occurs.
Infectious disease experts worldwide, working on Zika and other public health threats, put a priority on broad-spectrum antiviral drugs. Said Dr William Schaffner, a professor of preventive medicine at Vanderbilt University: “If you’re talking about my wish list, the first two things I would wish for, clearly, are a more precise diagnostic test and a safe and effective vaccine. Third on my list would be a therapeutic agent like this, especially one that one might employ during pregnancy.”