Ebola Outbreak: What to Consider if Experimental Vaccine Is Used

Updated May 22, 2017, 10:30 AM: A fourth person is suspected to have died from Ebola in the Democratic Republic of Congo (DRC). The total number of suspected cases has risen to 37.¹

A candidate vaccine for the Ebola virus, rVSV-ZEBOV, has been found to be highly effective in preventing virus development in exposed people. Researchers of the study, published in The Lancet, monitored areas in Africa where the 2015 Ebola virus outbreak occurred.  Results showed that immediate vaccination was highly effective in protecting vaccinated and unvaccinated individuals.²

While the video below questions whether the DRC will request use of the candidate vaccine for the current outbreak, “the US Food and Drug Administration regulatory agency is extremely unlikely to accelerate approval for this candidate vaccine based on this outbreak in the DRC in the absence of additional data on the safety, immunogenicity, and efficacy of this vaccine, beyond what was obtained during the recent epidemic in West Africa,” said Daniel R. Lucey, MD, MPH, a spokesman for the Infectious Diseases Society of America (IDSA), in an email interview with Infectious Disease Advisor.

As of May 16, 2017, more than 40 contacts spread over 4 affected health areas — Azande, Nambwa, Ngayi, and Muna — are being traced to ensure they do not develop the disease.³ If the outbreak is expanding, then a more likely decision would be to “perform a well-designed clinical study using the vaccine to try to help stop the outbreak,” noted Dr Lucey.

Dr Lucey stressed that “whenever this candidate vaccine or others are used in Ebola outbreaks, the studies must be performed in a safe and ethical manner, according to protocols that provide comprehensive and interpretable data, and that can be used to decide if prospectively defined endpoint criteria are met for licensure.”

References

1. WHO says fourth person dies from Ebola in the DRC [news release]. eNews Channel Africa. http://www.enca.com/africa/who-says-fourth-person-dies-from-ebola-in-the-drc Published May 22, 2017. Accessed May 22, 2017.
2.  Henao-Restrepo AM, Camacho A, Longini AM, et al. Efficacy and effectiveness of an rVSV-vectored vaccine in preventing Ebola virus disease: final results from the Guinea ring vaccination open-label, cluster randomized trial (Ebola Ça Suffit). Lancet. 2017;389:505-518. doi: 10.1016/S0140-6736(16)32621-6
3. DRC: response to the Ebola virus disease outbreak in Bas-Uele [news release]. Kinshasa, Democratic Republic of the Congo: World Health Organization Regional Office for Africa. http://www.afro.who.int/en/media-centre/pressreleases/item/9631-drc-response-to-the-ebola-virus-disease-outbreak-in-bas-uele.html Published May 17, 2017. Accessed May 18, 2017.