Vaccine Platforms for Marburg Virus

Introduction:

As of August 3, 2021, the WHO was made aware of a confirmed case of Marburg virus (MARV) illness (MVD) in Guinea, along with 173 contacts, 14 of whom were considered high risk due to their exposure. As this was the first detection of MARV in the country, concerns were expressed that the outbreak could spread and cause an epidemic similar to the one caused by the Ebola virus (EBOV) disease (EVD) in West Africa from 2013 to 2016. However, since September 16, when no new cases of MVD were found, the outbreak has been declared over in Guinea.

Two cases of MVD were reported to WHO on July 7, 2022, from the southern Ashanti area of Ghana; on July 15, 2022, the virus was confirmed to be MARV. The number of confirmed MVD cases increased to 3 on July 25, 2022, when two more cases were reported. Roughly 180 people were tracked in Ghana's Ashanti, Western, and Savannah regions. The constant reappearance of MARV emphasizes the importance of vaccines in preventing further MVD pandemics.

What Is Marburg Virus Disease (MVD)?

Marburg virus disease (MVD) is caused by a virus in the family Filoviridae resulting in hemorrhagic fever. Early signs of the disease include fever, chills, headaches, and muscle pains. As the disease progresses, the symptoms worsen and may lead to hemorrhagic fever and death. MVD is common in Africa, where up to 90 % fatality in those who contracted it. It can spread from person to person through blood and other body fluids. Marburg viruses have thread-like filaments (thread-like extension or fiber) that can look like a shepherd's crook, a "U," or a "6." They can also be coiled, toroid, or branched out. After getting infected with the virus, there is no cure, but early, professional intervention like vaccination can greatly help.

Many possible vaccines have been made, and the most promising ones are DNA vaccines, recombinant viral vector vaccines, and vaccines based on virus-like particles (VLP). These could protect nonhuman primates from getting sick from the Marburg virus.

Is There a Vaccine Available for Marburg Virus Disease?

Aside from supportive care, the FDA has approved no vaccines or specific treatments for MARV disease. Even though some experimental vaccines have been tried before, they are yet to be effective and long-lasting.

What Is "MARVAC" and Its Role in Developing Vaccines Against Marburg Virus Disease?

The World Health Organization (WHO) has managed MARVAC as a consortium to encourage global cooperation in the research and development of MVD vaccines. The success of the WHO's working groups on COVID-19 preclinical models and assays is leveraged by the collaboration to speed up the development of COVID-19 vaccines through the quick dissemination of scientific discoveries and protocols.

For maximum efficiency, this consortium has investors from the business world, the nonprofit sector, the public sector, and the academic community. Sharing assays and reagents, expanding access to laboratory networks in MVD-endemic countries, and facilitating the preclinical development of future MVD vaccines.

What Are Vaccine Platforms?

Vaccine platforms employ a base carrier or vehicle, such as a nucleic acid, viral vector, or liposome, which can be employed interchangeably to treat various diseases. Once a vaccine has been designed and approved, additional vaccines developed on the same platform would only involve swapping the appropriate antigenic component or a genetic molecule that generally induces an immune response. This would allow for faster and less expensive research, regulatory approval, and mass production. Vaccine platform technology is frequently described using terms like plug-and-play and cartridges.

There is no regulation unique to vaccination platforms in the United States, although many federal laws dealing with vaccines and other biological products are applicable. Furthermore, the Food and Drug Administration (FDA) and the United States Department of Agriculture (USDA), in charge of human and animal vaccination market approval, have numerous standards that pertain to platform technologies, at least in part. The World Health Organization (WHO) also provides rules for all member countries on vaccine research, manufacture, and regulation, including those particular to platform technology.

What Are the Vaccine Platforms for Marburg Virus?

Although actual virus treatment after infection is available, early, professional therapy, such as vaccination, is far more effective. Many potential vaccines have been developed, with DNA vaccines, recombinant viral vector vaccines, and virus-like particle (VLP)-based vaccinations being the most promising. All of these possibilities could protect nonhuman primates from Marburg virus-induced illness.

• DNA Vaccine: In relevant animal models, a multiagent DNA vaccine for highly pathogenic viruses known as biowarfare agents, Bacillus anthracis, Ebola, Marburg, and Venezuelan equine encephalitis virus, can elicit protective immunity. Furthermore, a test was developed to assess the effect of immune response in this vaccination and a mixture of all four vaccines; the results for both types were equal. As a result, the multiagent DNA vaccine possesses the potential of these four agents. It suggests a promising strategy for quickly producing multiagent vaccinations to prevent naturally occurring or purposely introduced diseases like the Marburg virus.

• Virus-Like Particle-Based Vaccine: Virus-like particle (VLP)-based vaccines get a lot of attention because they are similar in shape and antigenicity to the live virus they are made from. In making a vaccine against the Marburg virus, mammalian cells naturally made the glycoprotein and VP40 matrix protein from Lake Victoria marburgvirus (MARV) into VLPs. Marburg virus VLPs (mVLPs) were used to vaccinate Guinea pigs and macaques. Both types of animals developed humoral and T-cell responses and were completely protected from a lethal homologous MARV challenge. This showed that the mVLPs could protect against MVD in various animals. So, mVLPs can be a good choice because they have a wide range of immunity and protect against the Marburg virus.

• Recombinant Viral Vectors Vaccine: The vaccine was developed by exchanging VEE (Venezuelan Equine Encephalomyelitis) structural genes for those encoding Marburg virus glycoprotein, nucleoprotein, VP40, VP35, VP30, or VP24. If guinea pigs were immunized with either inactivated Marburg virus or a glycoprotein component, they would be protected from a fatal infection. VEE replicons expressing Marburg virus glycoprotein and nucleoprotein were inoculated into nonhuman primates as a more definite test of vaccine effectiveness. Those in the study who received vaccination with replicons expressing glycoprotein or nucleoprotein were fully protected from MVD (Marburg virus disease). It provides options for creating MVD vaccines.

Conclusion:

Marburg virus causes hemorrhagic fever and has an 88 % fatality rate. It belongs to the same family as of virus causing Ebola. Marburg virus causes sudden fever, severe headache, and severe malaise. Many people have severe hemorrhagic symptoms within seven days. Fruit bats transfer the virus to humans through their bodily fluids and surfaces. Virus vaccinations and antivirals are not licensed. Supportive care, oral or intravenous fluids, and symptom management improve survival rates.