Containing Ebola at the Source with Ring Vaccination.
Interim results from the Guinea Ebola ring vaccination trial suggest high efficacy of the rVSV-ZEBOV vaccine. These findings open the door to the use of ring vaccination strategies in which the contacts and contacts of contacts of each index case are promptly vaccinated to contain future Ebola virus disease outbreaks. To provide a numerical estimate of the effectiveness of ring vaccination strategies we introduce a spatially explicit agent-based model to simulate Ebola outbreaks in the Pujehun district, Sierra Leone, structurally similar to previous modelling approaches. We find that ring vaccination can successfully contain an outbreak for values of the effective reproduction number up to 1.6. Through an extensive sensitivity analysis of parameters characterising the readiness and capacity of the health care system, we identify interventions that, alongside ring vaccination, could increase the likelihood of containment. In particular, shortening the time from symptoms onset to hospitalisation to 2-3 days on average through improved contact tracing procedures, adding a 2km spatial component to the vaccination ring, and decreasing human mobility by quarantining affected areas might contribute increase our ability to contain outbreaks with effective reproduction number up to 2.6. These results have implications for future control of Ebola and other emerging infectious disease threats.
Bruno Kessler Foundation, Trento, Italy.
Stefano
S
Merler
Bruno Kessler Foundation, Trento, Italy.
Marco
M
Ajelli
Bruno Kessler Foundation, Trento, Italy.
Laura
L
Fumanelli
Bruno Kessler Foundation, Trento, Italy.
Stefano
S
Parlamento
Laboratory for the Modeling of Biological and Socio-technical Systems, Northeastern University, Boston, Massachusetts, United States of America.
Ana
A
Pastore Y Piontti
Department of Biostatistics, College of Public Health and Health Professions, University of Florida, Gainesville, Florida, United States of America.
Natalie E
NE
Dean
Doctors with Africa-CUAMM, Padua, Italy.
Giovanni
G
Putoto
Doctors with Africa-CUAMM, Padua, Italy.
Dante
D
Carraro
Department of Biostatistics, College of Public Health and Health Professions, University of Florida, Gainesville, Florida, United States of America.
Ira M
IM
Longini
Vaccine and Infectious Disease Division, Fred Hutchinson Cancer Research Center, Seattle, Washington, United States of America.|Department of Biostatistics, University of Washington, Seattle, Washington, United States of America.
M Elizabeth
ME
Halloran
Laboratory for the Modeling of Biological and Socio-technical Systems, Northeastern University, Boston, Massachusetts, United States of America.|Institute for Quantitative Social Sciences at Harvard University, Cambridge, Massachusetts, United States of America.|Institute for Scientific Interchange Foundation, Turin, Italy.
Alessandro
A
Vespignani
D046129:Ebola Vaccines / Q000008:administration & dosage*; D029043:Ebolavirus / Q000502:physiology*; D016701:Guinea / Q000453:epidemiology; D019142:Hemorrhagic Fever, Ebola / Q000453:epidemiology / Q000517:prevention & control*; D006801:Humans; D008954:Models, Biological; D012807:Sierra Leone / Q000453:epidemiology; D014611:Vaccination
D046129:Ebola Vaccines