Science Translational Medicine: Oral Drug Stops Early Measles Infection in Ferrets

Measles is making a comeback. Despite the existence of an effective vaccine for the highly infectious respiratory virus, the recent decline in vaccination compliance in some countries has led to an increase in sporadic outbreaks of the disease. Now, researchers have developed an oral drug that blocks a measles-like virus during the early stages of infection in ferrets.

It's important to note that the drug is not an alternative or replacement for proper vaccination; however, these results hint that its use could be a way to help eradicate the disease in regions with relatively low vaccination coverage. The drug could potentially be a preemptive treatment for preventing measles infection in non-vaccinated humans that may have come into contact with the disease, according to a report in the 16 April issue of Science Translational Medicine.

This thin-section transmission electron micrograph (TEM) reveals a single measles virus particle. | Cynthia Goldsmith/CDC

"This drug is not an alternative to measles vaccination, but an additional option," said Georgia State University researcher Richard Plemper, the paper's senior author, during a 15 April teleconference with reporters.

Like the flu, measles spreads through the air by breathing, sneezing and coughing. It is "so contagious that any child who is exposed to it and is not immune will probably get the disease," according to an overview of the disease on the Centers for Disease Control and Prevention website.

There is typically a two-week window between becoming infected and the onset of symptoms like skin rash, runny nose and fever. The antiviral drug developed by Stephanie Krumm at Georgia State University and colleagues is specifically designed to work during this two-week window, when vaccination can no longer protect from disease.

The small-molecule inhibitor works by targeting the viral RNA polymerase, an enzyme complex unique to the measles virus and a few other RNA viruses. The RNA polymerase is a virus replicator and fuels the expression of viral proteins. In ferrets with a lethal, measles-like disease, treatment with the drug three days after infection completely suppressed infection. All of the treated animals survived infection and developed immunity against the virus.

The researchers next plan to test the drug's safety and efficacy in larger animals, before moving into clinical trials in humans. Three of the paper's authors are inventors on a U.S. patent that includes the structure and method of use of the antiviral drug.