RVSV-ZEBOV

rVSV-ZEBOV is a vaccine used for the prevention of Ebola virus disease (EVD), caused by the Zaire ebolavirus species. The vaccine is based on a genetically engineered vesicular stomatitis virus (VSV), a virus that primarily affects cattle but can also infect humans, causing flu-like symptoms. In the rVSV-ZEBOV vaccine, a gene from the VSV has been replaced with a gene encoding the glycoprotein of the Zaire ebolavirus, enabling the vaccine to elicit an immune response against Ebola without causing the disease itself.

Development and Efficacy

The development of rVSV-ZEBOV was a response to the 2014-2016 Ebola virus epidemic in West Africa, one of the deadliest Ebola outbreaks in history. The vaccine was developed through a collaboration between various international health organizations, including the Public Health Agency of Canada, which initially developed the vaccine, and Merck Sharp & Dohme (MSD), a pharmaceutical company that further developed and produced the vaccine.

Clinical trials for rVSV-ZEBOV began during the West African Ebola outbreak and showed promising results. A notable trial conducted in Guinea, known as the "Ebola ça Suffit" trial, utilized a ring vaccination strategy, where contacts and contacts of contacts of confirmed Ebola virus disease cases were vaccinated. The trial demonstrated a high efficacy rate, with the vaccine showing 100% efficacy in those vaccinated, leading to its emergency use in outbreak situations even before it was officially licensed.

Licensing and Use

rVSV-ZEBOV received its first regulatory approval in 2019. It is now licensed for use in the European Union, the United States, and several African countries. The vaccine is considered a crucial tool in controlling outbreaks of Ebola virus disease, alongside other measures such as case isolation, contact tracing, and proper hygiene practices.

Administration and Side Effects

The rVSV-ZEBOV vaccine is administered as a single dose injection. Common side effects include injection site pain, headache, fever, muscle pain, and fatigue. These side effects are generally mild to moderate and resolve within a few days of vaccination. Severe allergic reactions are rare.

Future Directions

Research continues on the rVSV-ZEBOV vaccine to better understand its long-term efficacy and potential use in pediatric populations. Additionally, efforts are underway to explore the vaccine's effectiveness against other species of Ebola virus and to develop multivalent vaccines that can protect against multiple hemorrhagic fever viruses.

See Also

• Ebola virus disease
• Vaccine
• Epidemic
• Public Health Agency of Canada
• Merck Sharp & Dohme