1. GlaxoSmithKline Biologicals, Rixensart, Belgium
2. Frasch Biologics Consulting, Martinsburg, West Virginia
3. National Institute for Health and Welfare, Helsinki, Finland
4. Medical Research Council Respiratory and Meningeal Pathogens Research Unit & Department of Science and Technology/National Research Foundation, Vaccine Preventable Diseases, University of the Witswaterand, Johannesburg, South Africa