Vaccine Trials for Marburg Virus in Africa: A Race Against Time Amid Rising Outbreaks
In the heart of East Africa, Rwanda has launched a critical trial of a vaccine against the Marburg virus, a highly contagious and deadly disease that has killed 12 people in the country since it was declared an outbreak on September 27, 2024. This trial is part of a larger effort across the region to control the spread of the Marburg virus, a pathogen that shares a deadly resemblance to Ebola, another virus known for its hemorrhagic fevers and high fatality rates. The outbreak in Rwanda, along with cases in neighboring countries like Tanzania, has spurred an emergency response, highlighting the urgent need for an effective vaccine.
On October 6, Rwanda’s Health Minister, Sabin Nsanzimana, announced the start of vaccinations using an experimental vaccine provided by the U.S.-based Sabin Vaccine Institute. “The vaccination is starting today immediately,” Nsanzimana said during a news conference in Kigali, the nation’s capital. The vaccine, currently in phase 2 trials, has already undergone rigorous testing in Rwanda to meet local health and safety standards, with healthcare workers on the front lines being prioritized for inoculation.
Authorities have targeted groups most at risk of contracting the virus, including healthcare workers treating patients in intensive care units, emergency rooms, and treatment centers, as well as individuals who have come into close contact with confirmed cases. Nsanzimana expressed optimism about the vaccine’s potential, stating, “We believe that, with vaccines, we have a powerful tool to stop the spread of this virus.”
The Marburg virus, which is in the same family as the Ebola virus, was first identified in 1967 in Marburg and Frankfurt in Germany, as well as Belgrade, Serbia. It is believed to originate in fruit bats and spreads between humans through direct contact with bodily fluids or contaminated surfaces, such as bedsheets used by infected individuals. The virus causes severe hemorrhagic fever and can be fatal in up to 88 percent of cases, making it one of the most lethal pathogens known to affect humans.
Rwanda’s outbreak is not isolated; the region has been grappling with the virus for years. Tanzania, a neighboring country, announced its first outbreak of the Marburg virus disease (MVD) earlier this year. Five people have already died in Tanzania, with three additional cases confirmed in the Kagera region in the country’s northwest. Tanzania’s health authorities have identified approximately 161 people at risk of infection through contact tracing, with neighboring countries stepping up surveillance to prevent the virus from spreading further.
While Rwanda is working to contain its outbreak, health authorities across East Africa are collaborating with international organizations, including the World Health Organization (WHO) and the Africa Centres for Disease Control and Prevention (Africa CDC), to develop a unified response to the threat posed by the Marburg virus. Matshidiso Moeti, WHO’s regional director for Africa, commended Tanzania’s health officials for their quick response in identifying the disease and mobilizing resources to combat the outbreak. “We are working with the government to rapidly scale up control measures to halt the spread of the virus and end the outbreak as soon as possible,” Moeti stated.
In addition to Tanzania and Rwanda, Marburg outbreaks have occurred in other parts of Africa, including Equatorial Guinea, Ghana, Kenya, Uganda, and Angola. The most devastating outbreak took place in Angola between 2004 and 2005, where 252 cases were recorded, resulting in 227 deaths. This history of outbreaks highlights the enduring vulnerability of African nations to emerging infectious diseases, many of which, like Marburg and Ebola, have devastating effects on populations and healthcare systems.
The similarity between the Marburg and Ebola viruses has shaped much of the public health response to these outbreaks. Both viruses are transmitted through direct contact with infected bodily fluids and can cause hemorrhagic fevers that lead to severe internal bleeding, organ failure, and, in many cases, death. Symptoms of Marburg virus disease include fever, muscle pains, nausea, diarrhea, vomiting, and, in severe cases, jaundice and extreme blood loss.
The link between these two viruses goes beyond their clinical manifestations. The Ebola virus, responsible for several major outbreaks in West and Central Africa, has been the focus of global research efforts for decades. These efforts have led to the development of effective vaccines, which were first approved for use in 2019 after years of rigorous clinical trials. The lessons learned from the Ebola crisis, particularly the successful rollout of vaccines in West Africa, have informed the ongoing efforts to develop a vaccine for Marburg. The trial currently underway in Rwanda is based on this foundation.
The Sabin Vaccine Institute, which provided the experimental Marburg vaccine, is conducting phase 2 trials not only in Rwanda but also in Uganda and Kenya. According to a statement from the institute, the vaccine has not raised any safety concerns in the trials conducted thus far. In an initial shipment, approximately 700 doses of the vaccine were delivered to Rwanda, with more doses expected to follow as trials progress.
The ultimate goal of these trials is to replicate the success achieved with the Ebola vaccine, which dramatically reduced fatalities during the 2014–2016 West African Ebola outbreak. However, despite the promise of the experimental Marburg vaccine, there is still no definitive cure or treatment for the virus. According to the Centers for Disease Control and Prevention (CDC), the best way to improve a patient’s chances of survival is through supportive care, which involves managing symptoms, rehydration, and ensuring adequate oxygen levels. The absence of a proven cure underscores the critical importance of prevention, making vaccines an essential tool in the fight against Marburg virus disease.
Africa’s public health landscape has been shaped by a long history of outbreaks involving highly infectious diseases. The repeated emergence and re-emergence of diseases like Marburg, Ebola, and others illustrate the continent’s vulnerability to infectious disease threats. As Ahmed Ogwell Ouma, director of Africa CDC, stated, “These emerging and re-emerging infectious diseases are a sign that the health security of the continent needs to be strengthened to cope with the disease threats.” His comments reflect the broader call for greater investment in Africa’s public health infrastructure, particularly in disease surveillance, emergency response capabilities, and vaccine development.
The current outbreak in Rwanda, combined with Tanzania’s first experience battling the Marburg virus, serves as a stark reminder of the need for sustained international cooperation to prevent and contain these deadly pathogens. While the experimental vaccine trials offer a glimmer of hope, much remains to be done to stop the virus from spreading further and claiming more lives.
The ongoing vaccine trials in Rwanda, Uganda, and Kenya represent a vital step forward in the global effort to combat Marburg and other hemorrhagic fevers. If successful, the experimental vaccine could provide a powerful tool in future outbreaks, not just in Africa but globally. However, until the vaccine is fully approved and widely available, health authorities must remain vigilant, ensuring that proper hygiene, surveillance, and contact tracing protocols are in place to prevent the virus from spreading unchecked.
As the world continues to recover from the devastating COVID-19 pandemic, the emergence of Marburg and other infectious diseases serves as a sobering reminder of the persistent threat posed by zoonotic pathogens. The lessons learned from past epidemics must guide current and future efforts to strengthen Africa’s public health systems and prepare for the next inevitable outbreak.
Source: https://www.theguardian.com/global-development/2023/mar/22/tanzania-announces-outbreak-of-deadly-marburg-virus-disease
https://www.aljazeera.com/news/2024/10/6/rwanda-begins-vaccination-drive-to-curb-marburg-virus-outbreak