Scientists have developed a strain of the Middle East respiratory syndrome coronavirus (MERS-CoV) that could be used as a vaccine against the disease, according to a study to be published in mBio, the online open-access journal of the American Society for Microbiology. The mutant MERS virus, rMERS-CoV-ΔE, has a mutation in its envelope protein that makes it capable of infecting a cell and replicating its genetic material, but deprives it of the ability to spread to other tissues and cause disease. The authors say once additional safe guards are engineered into the virus, it could be used as the basis of a safe and effective live-attenuated vaccine against MERS.
"Our achievement was a combination of synthetic biology and genetic engineering," says co-author Luis Enjuanes of The Autonomous University of Madrid (Universidad Autnoma de Madrid).
"The injected vaccine will only replicate in a reduced number of cells and produce enough antigen to immunize the host," he says, and it cannot infect other people, even those in close contact with a vaccinated person.
Since MERS was first identified in June 2012, the World Health Organization has been notified of 108 cases of infection, including 50 deaths. Although the total number of cases is still relatively small, the case fatality rate and the spread of the virus to countries beyond the Middle East is alarming to public health officials. If the virus evolves the ability to transmit easily from person to person, a much more widespread epidemic is possible. Diagnostic assays and antiviral therapies for MERS have been described, but reliable vaccines have not yet been developed.
Enjuanes and his team applied what they had learned from 30 years of research on the molecular biology of coronaviruses to synthesize an infectious cDNA clone of the MERS-CoV genome based on a published sequence. They inserted the viral cDNA chromosome into a bacterial artificial chromosome, and m
|Contact: Jim Sliwa|
American Society for Microbiology