January 7, 2025
For over 20 years, the Public Health Agency of Canada (PHAC)’s National Microbiology Laboratory (NML) has been conducting research on Marburg virus to help save lives in countries experiencing outbreaks and to protect the health and safety of people in Canada. Marburg virus disease is a rare and often fatal illness caused by the Marburg virus. It belongs to a group of viruses known as filoviruses, which includes Ebola. With a fatality rate between 24% and 88%, and no approved treatments or vaccines at this time, there is an urgent need for more research into this deadly virus, especially as outbreaks continue to occur.
Uniquely positioned to address the threat of Marburg
As a Risk Group 4 pathogen, researchers can only work on the Marburg virus in a containment level (CL4) laboratory. Since the Canadian Science Centre for Human and Animal Health (CSCHAH), home to the NML, has Canada’s only containment level (CL4) laboratory, the NML is uniquely positioned to study Marburg and bring its expertise to support global public health. The NML plays a key role in providing on-the-ground support during international outbreaks, including in 2004-2005, when the largest outbreak of Marburg happened in Angola, where 252 cases were recorded and 227 individuals died. The NML supported the response by operating a mobile laboratory unit that provided in-country diagnostics to assist with patient management, infection control and contact tracing.
Dr. Logan Banadyga, a Senior Research Scientist at the NML, says that this work helps to protect not only people directly affected by the disease, but also people in Canada.
“People often think of viruses like Marburg or Ebola as being diseases of other continents,” says Dr. Banadyga. “In today’s super-connected world, public health in Africa is public health in Canada.”
Vaccines and treatments
The NML has a long history of conducting impactful research on Marburg virus, dating back to 2004, when scientists at the lab first developed a vesicular stomatitis virus (VSV) vector that could function as a vaccine, called VSV-MARV, to prevent Marburg virus disease. VSV-MARV uses the same technology as the Ebola vaccine, known as VSV-EBOV, which was used successfully during the 2014 Ebola outbreak in West Africa.
Since 2019, the NML has collaborated with a company called Public Health Vaccines, who licensed the VSV-MARV technology from PHAC, on a VSV-MARV vaccine that is currently in phase I clinical trials. The NML continues to conduct studies with this vaccine candidate to better understand the immune response, including how long the vaccine provides protection after immunization.
In addition, the NML has contributed to the development of a T-cell vaccine that has demonstrated complete protection against Ebola and Marburg viruses in mice. The NML continues to work with other international scientists to investigate other vaccine platforms, including those that protect against multiple viral hemorrhagic fevers.
On the treatment front, the NML has been developing and characterizing monoclonal antibodies against Marburg virus, some of which have potential to be used as medications. In 2019, NML scientists contributed to the discovery of a pan-filovirus antibody cocktail that could protect non-human primates against Marburg, Ebola and Sudan viruses.
Diagnostics
Hand-in hand with vaccines and treatments, the NML is working on improving diagnostics for Marburg virus. They developed a polymerase chain reaction (PCR) molecular test that detects at least six different variants of Marburg at exceptionally low levels and has the capability to quickly conduct whole genome sequencing to augment PCR testing if necessary.
In addition, scientists are working on a rapid antigen test using antibodies, capable of detecting Marburg virus from a liquid sample. These rapid tests can be used on-site and show results in 15 minutes, which will be very useful in an outbreak.
Also in development is a blood test that can detect an immune response from Marburg virus in a variety of different animals. This test will not only be used to advance scientific research projects, but it can also be used to test human samples as needed.
NML expertise key to ongoing efforts and preparedness in Canada
The lab’s expertise in Marburg virus is key to ongoing research projects, diagnostic efforts and preparedness measures globally and in Canada. If a suspected case of Marburg virus were to occur in Canada, samples from the individual would be sent to the NML for analysis where the lab is well-prepared and trained for such a scenario. The lab is also working with Canadian hospitals to help them prepare in the event of a suspected case.
“We’re fortunate to be doing the kind of research that will lead to life-saving vaccines and treatments as well as faster diagnosis techniques,” says Dr. Banadyga. “Being able to improve public health conditions in places where these viruses are endemic will indirectly benefit Canada by preventing outbreaks of these viruses from getting large enough to export cases around the world.”