Re: The ring vaccination trial: a novel cluster randomised controlled trial design to evaluate vaccine efficacy and effectiveness during outbreaks, with special reference to Ebola
We read with interest the above article. First, we congratulate the authors for this novel idea of using RCT for Ring Immunisation. Our experience in India has been restricted to control of Out breaks of smallpox, measles, Polio and Viral hepatitis A as a part of health services. This will be a great value addition in outcome research in low resource countries but we would be grateful if the authors could communicate the criterion for deciding the size of the ring.
Competing interests: No competing interests