Ervebo Ebola Vaccine: DRC Receives 70,000 Doses Amid Outbreak

UPSC Mapping

Exam	Topic
Prelims	Health & Diseases
Mains	GS Paper 2 (Health & International Relations)

Quick Facts

Type	Live-attenuated recombinant vector
Target Virus	Zaire ebolavirus (not Bundibugyo)

What is Ervebo Ebola Vaccine?

Ervebo (rVSV-ZEBOV) is a single-dose vaccine designed to protect against Ebola virus disease caused by the Zaire ebolavirus. It is a live, replication-competent recombinant viral vector vaccine that uses a genetically engineered vesicular stomatitis virus (VSV) vector expressing an Ebola virus glycoprotein. This glycoprotein triggers an immune response that protects against Ebola infection.

Ervebo was developed by Merck and was first approved by the US FDA in December 2019 and by the European Medicines Agency in 2020. It has been used in ring vaccination strategies during previous Ebola outbreaks, particularly in West Africa and the DRC. However, it is not effective against other species of the Ebola virus, such as the Bundibugyo virus, which is causing the current outbreak.

Why is Ervebo Ebola Vaccine in News?

The Ervebo Ebola vaccine is in the news because the DRC is receiving 70,000 doses to combat a rapidly worsening Ebola outbreak. However, the vaccine is only effective against the Zaire ebolavirus, while the current outbreak is caused by the Bundibugyo virus. This means that Ervebo may not be fully effective, and health authorities are exploring other options, including the use of other experimental vaccines or treatments.

The situation underscores the challenges of developing broad-spectrum vaccines against the Ebola virus, which has multiple species. It also highlights the importance of rapid diagnostics and international cooperation in responding to outbreaks. For official updates, refer to the WHO situation reports.

Key Features of Ervebo

• Single-Dose Regimen: Provides protection after a single injection, simplifying logistics in outbreak settings.
• Live-Attenuated Vector: Uses a vesicular stomatitis virus vector to deliver Ebola glycoprotein antigens.
• Proven Efficacy: Demonstrated high efficacy in clinical trials and real-world use during outbreaks of Zaire ebolavirus.
• Licensed Use: Approved in the US, EU, and several other countries for use in adults.
• Species-Specific: Not effective against other Ebola virus species like Bundibugyo or Sudan viruses.

Challenges in Ebola Vaccination

• Species Diversity: Multiple Ebola virus species with distinct glycoproteins require different vaccines.
• Supply Chain: Maintaining a stockpile of vaccines and distributing them in remote areas is logistically challenging.
• Vaccine Hesitancy: Mistrust and misinformation can reduce vaccine uptake in affected communities.
• Cost and Storage: The vaccine requires cold chain storage, which is difficult in resource-poor settings.

Way Forward for Ebola Preparedness

To improve global preparedness for Ebola outbreaks, research and development should focus on multivalent vaccines that cover all Ebola virus species. Strengthening surveillance systems and building rapid response capacities in endemic countries are equally important. The international community should support the DRC and other at-risk nations with funding, training, and technical assistance.

As highlighted by a CDC report, proactive investment in public health infrastructure can prevent outbreaks from escalating into epidemics.

Prelims Practice Corner

Q1. Which virus does Ervebo vaccine protect against?

• (a) Bundibugyo virus
• (b) Zaire ebolavirus
• (c) Sudan virus
• (d) Marburg virus

Answer: (b) Zaire ebolavirus.

Q2. What type of vaccine is Ervebo?

• (a) Inactivated virus
• (b) Live-attenuated recombinant vector
• (c) mRNA
• (d) Protein subunit

Answer: (b) Live-attenuated recombinant vector.

Q3. Which country is currently receiving 70,000 doses of Ervebo?

• (a) Nigeria
• (b) DRC
• (c) Uganda
• (d) Ghana

Answer: (b) DRC.

Q4. What is the primary limitation of Ervebo?

• (a) Side effects
• (b) Species-specific protection
• (c) High cost
• (d) Need for multiple doses

Answer: It is only effective against Zaire ebolavirus, not other species.

Q5. Who developed Ervebo?

• (a) Pfizer
• (b) Merck
• (c) Johnson & Johnson
• (d) Novavax

Answer: (b) Merck.

Mains Practice Questions

Q1. “The Ervebo Ebola vaccine’s limitation to a single species highlights the need for broader research and development in global health security.” Discuss the challenges and opportunities in developing multivalent vaccines for emerging infectious diseases. (250 words, 15 marks)

Answer Structure:

• Intro: Introduce Ervebo and its species specificity.
• Body: Discuss the challenges of multiple Ebola species, the need for broad-spectrum vaccines, and the role of international collaboration in outbreak response.
• Conclusion: Emphasise the importance of investing in R&D for pandemic preparedness.

Q2. “Global health security is only as strong as its weakest link.” Evaluate the response to the Ebola outbreak in the DRC and the role of vaccines like Ervebo in controlling outbreaks. (250 words, 15 marks)

Answer Structure:

• Intro: Highlight the global importance of containing Ebola outbreaks.
• Body: Discuss the DRC’s outbreak, the use of Ervebo, its limitations, and the need for rapid diagnostics, community engagement, and international support.
• Conclusion: Conclude with recommendations for strengthening global health systems.

FAQs on Ervebo Ebola Vaccine

Is Ervebo effective against all Ebola virus strains?

No, Ervebo is only licensed for the Zaire ebolavirus. It is not effective against other species like Bundibugyo, Sudan, or Taï Forest viruses.

How is Ervebo administered?

It is given as a single-dose injection, usually in the upper arm.

Why is the current DRC outbreak problematic for Ervebo use?

The current outbreak is caused by the Bundibugyo virus, against which Ervebo is not effective, reducing its utility in controlling the spread.