In News:

The World Health Organization (WHO) declared the Bundibugyo Ebola Virus Disease (BVD) outbreak in the Democratic Republic of the Congo (DRC) and Uganda as a Public Health Emergency of International Concern (PHEIC).

The outbreak has drawn global attention because, unlike the Zaire strain of Ebola, there is currently no licensed vaccine or specific treatment for the Bundibugyo virus, exposing serious gaps in global preparedness against emerging infectious diseases.

What is Bundibugyo Virus?

• Bundibugyo virus is one of the six species of the Orthoebolavirus genus that causes Ebola Virus Disease (EVD).
• It is a zoonotic disease, with fruit bats believed to be its natural reservoir. Human infection occurs through contact with infected wildlife such as bats and non-human primates, while subsequent transmission takes place through direct contact with the blood, body fluids, or contaminated objects of infected individuals. Healthcare workers and people participating in unsafe burial practices are particularly vulnerable to infection.
• The virus has an incubation period of 2–21 days, and infected individuals become contagious only after symptoms appear.
• Initial symptoms such as fever, fatigue, headache, muscle pain, and sore throat resemble common febrile illnesses like malaria, making early diagnosis difficult.
• In severe cases, patients develop gastrointestinal complications, multi-organ failure, and haemorrhagic manifestations.
• Previous outbreaks in Uganda and the DRC have reported case fatality rates ranging from 30% to 50%. Diagnosis requires laboratory confirmation through RT-PCR and antigen or antibody-based tests.

Ebola Virus Disease:

• Ebola Virus Disease is a rare but highly fatal viral haemorrhagic fever first identified in 1976 near the Ebola River in the DRC.
• Of the six known Orthoebolavirus species, Ebola virus, Sudan virus, Bundibugyo virus, and Taï Forest virus infect humans, while Reston and Bombali viruses have not caused human disease.
• Although WHO has approved monoclonal antibody therapies such as Ansuvimab and Inmazeb, and vaccines like Ervebo, Zabdeno, and Mvabea, these are effective only against the Zaire Ebola virus.
• No approved vaccine or targeted therapy currently exists for Bundibugyo or Sudan virus disease, making supportive care, rapid case detection, isolation, contact tracing, infection prevention, and safe burial practices the primary means of controlling outbreaks.

Why has vaccine development been delayed?

The Bundibugyo outbreak highlights a classic case of market failure in global health. Vaccine development is scientifically complex, expensive, and requires high-containment Biosafety Level-4 (BSL-4) laboratories and lengthy clinical trials. Since Bundibugyo outbreaks are infrequent and largely confined to low-income African countries with limited purchasing power, pharmaceutical companies have little commercial incentive to invest in vaccine research. Consequently, diseases with high public health risks but limited market demand continue to remain neglected, despite posing significant pandemic threats.