Other common side-effects were pain at the site of injection, myalgia, and fatigue.[15] The trial was temporarily halted in December 2014 due to possible adverse effects, but subsequently resumed.[16] As of April 2015[update], a Phase III trial with a single dose of VSV-EBOV began in Liberia after a successful Phase II study in the West African country.[6] On 31 July 2015, preliminary results of a Phase III trial in Guinea indicated that the vaccine appears to be "highly efficacious and safe."[18] The trial used a ring vaccination protocol that first vaccinated all the closest contacts of new cases of Ebola infection either immediately or after 21 days.