PreVail I cluster vaccination study with RVSVDG-Zebov-GP as part of a public health response in Liberia

Fatorma K. Bolay, Greg Grandits, H. Clifford Lane, Stephen B. Kennedy, Melvin P. Johnson, Mosoka P. Fallah, Barthalomew Wilson, Wissedi S. Njoh, Laura A. McNay, Lisa E. Hensley, Elizabeth S. Higgs

Research output: Contribution to journalArticlepeer-review

11 Scopus citations


Objective: In November 2015, a 15-year-old boy received a diagnosis of Ebola virus disease (EVD) at the John F. Kennedy Medical Center in Monrovia, Liberia. Two additional family members received a diagnosis of EVD. The protocol for a phase 2 placebo-controlled trial of 2 Ebola vaccines was amended and approved; in 4 days, a single-arm cluster vaccination trial using the Merck rVSVDG-ZEBOV-GP vaccine was initiated. Here, we evaluate the safety and immunogenicity of the vaccine and discuss challenges for its implementation in a small Ebola outbreak. Method: We conducted a ring vaccination study among contacts and contacts of close contacts of EVD cases a in Monrovia. Participants were evaluated 1 and 6 months after vaccination. Results: Among 650 close contacts and contacts of close contacts of EVD cases, 210 (32%) consented and were vaccinated with rVSVDG-ZEBOV-GP. Of those vaccinated, 189 (90%) attended the month 1 follow-up visit; 166 (79%) attended the month 6 visit. No serious adverse events were reported. Among 88 participants without an elevated antibody level at baseline, 77.3% (95% confidence interval, 68.5-86.1) had an antibody response at 1 month. Conclusions: The Merck rVSVDG-ZEBOV-GP vaccine appeared to be safe and immunogenic among the vaccinated individuals. However, fewer than one third of eligible individuals consented to vaccination. These data may help guide implementation decisions for of cluster vaccination programs in an Ebola cluster outbreak response situation.

Original languageEnglish (US)
Pages (from-to)1634-1641
Number of pages8
JournalJournal of Infectious Diseases
Issue number10
StatePublished - May 1 2019

Bibliographical note

Publisher Copyright:
© The Author(s) 2019.


  • Cluster vaccination
  • Ebola virus
  • Ebola virus disease
  • Liberia
  • Outbreak response
  • RVSVDG-ZEBOV-GP vaccine
  • Ring vaccination
  • Vaccine

PubMed: MeSH publication types

  • Research Support, Non-U.S. Gov't
  • Journal Article
  • Research Support, N.I.H., Extramural


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