Understanding Filoviridae: Ebola and Sudan Virus Outbreaks and Impact
- According to health agency data, the virus family Filoviridae includes several species capable of causing severe and often fatal disease in humans, with the genus Orthoebolvirus accounting for...
- In addition to the Zaire species, Orthoebolvirus sudanense, known as the Sudan virus, and Orthoebolvirus bundibugyoense, known as the Bundibugyo virus, have both caused substantial outbreaks.
- To address prevention, the Advisory Committee on Immunization Practices recommended pre-exposure vaccination with the rVSVΔG-ZEBOV-GP vaccine on February 26, 2020.
According to health agency data, the virus family Filoviridae includes several species capable of causing severe and often fatal disease in humans, with the genus Orthoebolvirus accounting for the majority of clinical cases and associated deaths. Within this genus, Orthoebolvirus zairense, commonly known as the Ebola virus, triggered a massive epidemic in West Africa between 2013 and 2016 that resulted in at least 28 000 clinical cases and 11 325 deaths.1
Outbreak Scope and Re-emergence
In addition to the Zaire species, Orthoebolvirus sudanense, known as the Sudan virus, and Orthoebolvirus bundibugyoense, known as the Bundibugyo virus, have both caused substantial outbreaks. According to outbreak tracking data, the Bundibugyo virus recently re-emerged in the Democratic Republic of the Congo. As of August 27, 2026, that specific re-emergence has caused 5815 confirmed cases and 2788 deaths.
Federal Vaccine Recommendations and Review Methods
To address prevention, the Advisory Committee on Immunization Practices recommended pre-exposure vaccination with the rVSVΔG-ZEBOV-GP vaccine on February 26, 2020. According to the Centers for Disease Control and Prevention, the recommendation applies to adults aged 18 years or older in the United States population who face potential exposure to the Ebola virus. This group includes outbreak response personnel, healthcare workers at federally designated Ebola Treatment Centers, and staff at biosafety-level 4 facilities. Prior to this 2020 decision, the advisory committee maintained no specific recommendations for vaccines to prevent Ebola virus disease. Beginning in September 2019, the committee’s Ebola Vaccine Work Group met regularly to define research questions, identify patient-centered outcomes, conduct a systematic evidence review, and apply the Grading of Recommendations Assessment, Development and Evaluation approach. No conflicts of interest were reported by the federal agency staff or work group members involved in the review.
Evidence Synthesis and Literature Search
On December 16, 2019, researchers executed a broad literature search across multiple biomedical and interdisciplinary bibliographic databases without date or language restrictions to identify relevant studies on the rVSVΔG-ZEBOV-GP vaccine. The search strategy was updated on January 31, 2020, to capture recent records, while subject matter experts and the manufacturer contributed one additional unpublished record. The review screened records involving immunocompetent adults aged 18 years or older, regardless of pregnancy status, who received the intervention. Database searches and supplementary sources identified 1,818 total records, of which 1,742 were excluded during title and abstract screening. Full-text review assessed 77 articles for eligibility, leading to the exclusion of 59 additional studies. Ultimately, 18 articles presenting data from 11 studies entered qualitative synthesis, while 9 articles from 8 studies contributed to quantitative synthesis and meta-analysis, according to federal documentation.