December 11, 2014
By Mark Terry, BioSpace.com Breaking News Staff
A clinical trial of an experimental Ebola vaccine co-developed by Merck and NewLink, has been paused at Geneva University Hospital (Switzerland) after four of 59 participants complained of joint pain in their hands and feet. The trials are expected to continue on Jan.5, 2015 in 15 more volunteers once additional tests are completed to confirm that the pain was benign and temporary.
On Nov. 24 the two companies inked a deal to develop, manufacture and distribute NewLinks’ Ebola vaccine candidate. The vaccine, rVSV-EBOV, was developed by the Public Health Agency of Canada (PHAC). The U.S. National Institutes of Health (NIH) plan to begin a randomized, controlled Phase III trial of the vaccine in 2015, as well as of another Ebola vaccine co-developed by the National Institute of Allergy and Infectious Diseases (NIAID) and GlaxoSmithKline (GSK).
“Effective Ebola vaccines will be a critical component of comprehensive prevention and control measures for people at risk of Ebola virus infection and to stem future outbreaks globally,” said Merck Vaccines President Julie Gerberding, in a statement in November. “Merck is committed to applying our vaccine expertise to address global health needs and, through our collaboration with NewLink, we hope to advance the public health response to this urgent international health priority.”
The vaccine candidate, rVSV-EBOV, is part of NewLink’s rVSV Vaccine Platform. This technology uses an attenuated strain of a vesicular stomatitis virus. A bit of the Ebola virus genetic code is inserted into the vesicular stomatitis virus, making it produce an Ebola virus protein. This stimulates the patient’s immune system to produce antibodies against the Ebola virus.
Geneva Hospital’s statement says that, “Initial results show that the vaccination is very well tolerated. In the hours and days following the injection, some volunteers had some fever or muscle pain; these reactions were expected and participants were informed about them during the medical consultation which took place before their inclusion in the study.”
Because the mild joint pain in the hands and feet were unexpected, the hospital paused the injections. The statement does indicate that joint pain after infection or vaccination is very common. “This is a well-documented phenomenon which does not worry specialists. However, it deserves to be carefully studied in order to update the information which is provided to the volunteers. The temporary interruption of a clinical trial is a standard precautionary measure in such cases.”
In addition to the Geneva, Switzerland site, similar studies are being conducted in the U.S., Canada, Germany and Gabon. To date, similar inflammatory symptoms have not been observed in the other trial locations.
